It’s come round again. Christmas time. Emma and I wish you all good cheer and best wishes this winter season whatever your religious leanings are.
For the first time in many years my family will be split up on Christmas day this year.
My husband will be working on a boat in the North Sea and he is hoping they don’t serve sheep’s head for dinner this year. I’m not kidding. This is a Norwegian “speciality” and it is very much a Marmite thing. Another thing he can’t stand, but could be faced with is fish that has been buried for a while in the ground. Here is hoping that your holiday feast will be better than traditional Norwegian fare.
My diabetic son will be staying in London with his girlfriend so she won’t be spending Christmas alone. She is a midwife in a London hospital and has a lot of shifts rostered over the period.
My younger son will be travelling home for Christmas so we will have a nice meal of some kind but don’t intend to do our usual Gordon Ramsay’s ham in mustard and treacle as we will have Christmas dinner on New Year’s day instead. This is where my fantastic low carb/gluten free tiramisu also shines.
It will be a bit sad this year because two of our four cats died this year of cancer. One death was long expected at age almost 17 and the other was quick and unexpected at 9.5 years. The usual bevvy of expectant wee faces will be missing this year.
Recently I bought the Meta Quest 3 so I won’t be getting any expensive stuff this year (since I’ve already done the deed). I had bought myself the Quest 1 four years ago but it is now obsolete. I absolutely love the upgraded visual effects and expect the boys to love it too.
I hope you all have an enjoyable day, and if you are unable to celebrate on the actual day, like many other workers, patients, or simply due to transport problems, I hope your proxy fun day is just as good as you hope.
1Department of Neurology, NYU Grossman School of Medicine, New York, NY, United States
2NYU Health Sciences Library, New York, NY, United States
Importance:Non-communicable chronic diseases (NCDs) such as obesity, type 2 diabetes, heart disease, and cancer were rare among non-western populations with traditional diets and lifestyles. As populations transitioned toward industrialized diets and lifestyles, NCDs developed.
Objective: We performed a systematic literature review to examine the effects of diet and lifestyle transitions on NCDs.
Evidence Review: We identified 22 populations that underwent a nutrition transition, eleven of which had sufficient data. Of these, we chose four populations with diverse geographies, diets and lifestyles who underwent a dietary and lifestyle transition and explored the relationship between dietary changes and health outcomes. We excluded populations with features overlapping with selected populations or with complicating factors such as inadequate data, subgroups, and different study methodologies over different periods. The selected populations were Yemenite Jews, Tokelauans, Tanushimaru Japanese, and Maasai. We also review transition data from seven excluded populations (Pima, Navajo, Aboriginal Australians, South African Natal Indians and Zulu speakers, Inuit, and Hadza) to assess for bias.
Findings:The three groups that replaced saturated fats (SFA) from animal (Yemenite Jews, Maasai) or plants (Tokelau) with refined carbohydrates had negative health outcomes (e.g., increased obesity, diabetes, heart disease). Yemenites reduced SFA consumption by >40% post-transition but men’s BMI increased 19% and diabetes increased ~40-fold. Tokelauans reduced fat, dramatically reduced SFA, and increased sugar intake: obesity and diabetes rose. The Tanushimaruans transitioned to more fats and less carbohydrates and used more anti-hypertensive medications; stroke and breast cancer declined while heart disease was stable. The Maasai transitioned to lower fat, SFA and higher carbohydrates and had increased BMI and diabetes. Similar patterns were observed in the seven other populations.
Conclusion:The nutrient category most strongly associated with negative health outcomes – especially obesity and diabetes – was sugar (increased 600–650% in Yemenite Jews and Tokelauans) and refined carbohydrates (among Maasai, total carbohydrates increased 39% in men and 362% in women), while increased calories was less strongly associated with these disorders. Across 11 populations, NCDs were associated with increased refined carbohydrates more than increased calories, reduced activity or other factors, but cannot be attributed to SFA or total fat consumption.
Key Points
Question: What dietary factors contribute to non-communicable chronic diseases (NCDs) among populations transitioning from their original to westernized diets?
Findings: Our systemic literature review examined four populations that transitioned from their original to a more westernized diet and lifestyle. We also reviewed seven additional populations that underwent a similar transition. We identified a strong association between NCDs and increased sugar and refined carbohydrate consumption, and weaker associations with increased total calories with reduced physical activity. Neither fat nor saturated fat intake were associated with risk of developing NCDs in any of the populations.
Meaning: Increased consumption of sugar and refined carbohydrates were strongly associated with the development of NCDs in all four populations. Increased calories and decreased physical activity were less strongly correlated although both of these measures are imprecisely defined and not quantified in any of these group. Neither fat nor saturated fat intake were associated with NCD risk in any population.
The “carnivore diet,” based on animal foods and excluding most or all plant foods, has attracted recent popular attention. However, little is known about the health effects and tolerability of this diet, and concerns for nutrient deficiencies and cardiovascular disease risk have been raised.
We obtained descriptive data on the nutritional practices and health status of a large group of carnivore diet consumers.
A social media survey was conducted 30 March–24 June, 2020 among adults self-identifying as consuming a carnivore diet for ≥6 mo. Survey questions interrogated motivation, dietary intake patterns, symptoms suggestive of nutritional deficiencies or other adverse effects, satisfaction, prior and current health conditions, anthropometrics, and laboratory data.
A total of 2029 respondents (median age: 44 y, 67% male) reported consuming a carnivore diet for 14 mo (IQR: 9–20 mo), motivated primarily by health reasons (93%). Red meat consumption was reported as daily or more often by 85%. Under 10% reported consuming vegetables, fruits, or grains more often than monthly, and 37% denied vitamin supplement use.Prevalence of adverse symptoms was low (<1% to 5.5%). Symptoms included gastrointestinal (3.1%–5.5%), muscular (0.3%–4.0%), and dermatologic (0.1%–1.9%). Participants reported high levels of satisfaction and improvements in overall health (95%), well-being (66%–91%), various medical conditions (48%–98%), and median [IQR] BMI (in kg/m2) (from 27.2 [23.5–31.9] to 24.3 [22.1–27.0]). Among a subset reporting current lipids, LDL-cholesterol was markedly elevated (172 mg/dL), whereas HDL-cholesterol (68 mg/dL) and triglycerides (68 mg/dL) were optimal. Participants with diabetes reported benefits including reductions in median [IQR] BMI (4.3 [1.4–7.2]), glycated hemoglobin (0.4% [0%–1.7%]), and diabetes medication use (84%–100%).
Contrary to common expectations, adults consuming a carnivore diet experienced few adverse effects and instead reported health benefits and high satisfaction. Cardiovascular disease risk factors were variably affected. The generalizability of these findings and the long-term effects of this dietary pattern require further study.
My comment: I have summarised the full articleand have removed most of the tables.You will be able to find the full article online should you wish to examine these in more depth.
Introduction
Dietary variety is near-universally recommended in National Guidelines to satisfy human nutritional needs (1, 2). Consumption of a variety of food groups from both plant and animal food sources has been linked to favorable health outcomes in epidemiologic studies (3) and clinical trials (4–6) and is expected to satisfy the recommended DRIs of macronutrients (i.e., protein, carbohydrates, and fats), micronutrients (i.e., vitamins and minerals), and food components (e.g., dietary fiber).
Nevertheless, restrictive diets have long been promoted for various health and philosophical reasons. One notable eating pattern, a vegan diet, that eliminates animal foods has been promoted for ethical (7), environmental (8), and health (9) benefits—including reduction in BMI, improvement in serum lipids, and cancer prevention (9). However, these reported benefits may be confounded by dietary and nondietary health behaviors, and negative effects have also been reported (10). Vegan diet consumers may not meet DRIs for vitamin B-12, calcium, and protein, and adverse events, such as an increased incidence of bone fractures (11), have been observed.
Recently, popular interest has grown in an opposite eating pattern, a carnivore diet, which aims to eliminate most or all plant-based foods. Numerous social media groups (e.g., https://www.facebook.com/groups/worldcarnivoretribe/) have been formed, with membership of many thousands in the United States and other nations, to promote this diet for health and other benefits. Whereas diets high in animal foods have been commonly discouraged owing to high saturated fats content and low density of essential nutrients and bioactive compounds (e.g., fiber, phytonutrients) (12), little is known about the health status of people habitually following a carnivore eating pattern. According to a common view, long-term consumption of a strictly animal-based diet would be associated with significant nutritional deficiencies (13) and confer negative health effects compared with a plant-based diet (14, 15), including poor gut and gut-microbiota health (16–19), an adverse cardiovascular disease risk pattern (20, 21), and other chronic health complications (22).
What little evidence exists for the sustainability of carnivore diets derives from historic reports on Arctic or nomadic societies, clinical case studies, and accounts on nutrition therapy for diabetes mellitus in the preinsulin era c.1920. Early reports by Arctic researchers and population surveys provide evidence that animal-based diets with little to no plant matter were consumed by traditional populations at high latitude during most of the year (23–25), and were associated with good health and longevity (26, 27). Inspired by their experiences, 2 Arctic explorers participated in a study, partly conducted under strict inpatient observation, of a diet containing only meat (27). After 1 y, they reported good health and displayed no clinical evidence of any vitamin deficiency, although a negative calcium balance was reported (28). Of note, the animal-based diets consumed in this study incorporated both lean and fatty meats, including a variety of organ meats; these were frequently boiled, and sometimes consumed raw, with potential implications for the availability of low-concentration or labile nutrients. Likewise inspired by observations on an indigenous diet in St. Lucia, Dr. John Rollo in 1797 successfully treated 2 patients with diabetes with a diet consisting only of meat and fat. Rollo recommended near-complete elimination of plant foods (29), a prescription that was widely adopted and empirically optimized to prolong the life of people with diabetes in the 19th century. Recognizing the link between carbohydrate intake and glucosuria, some physicians allowed intake of low-carbohydrate vegetables (30), whereas others promoted a strictly meat- and fat-based approach for diabetes management [e.g., Cantani, Primavera (31)]. With the discovery of insulin, these dietary approaches were abandoned in favor of less restrictive mixed diets (32), and modern research on an animal-based diet is sparse.
Although several contemporary treatments of obesity or type 2 diabetes promote high intake of meat and fat (e.g., the Atkins diet) (33), these diets typically include, or reintroduce after short periods, consumption of low-carbohydrate vegetables and low-sugar fruits. Whereas a recent perspective suggests that all essential nutrients can be obtained from a carnivore diet (34), few empirical data are available. Therefore, the aim of this study was to characterize the motivation, dietary behaviors, self-perceived health status, and satisfaction of a large group of adults habitually consuming a carnivore diet, and thereby to provide insights into this poorly characterized dietary approach.
Methods
Design
Using an online survey, we collected self-reported data from respondents who self-identified as following a carnivore diet for a minimum of 6 mo. Our aims were to 1) characterize the diet consumed by parti-cipants, 2) describe perceived health status and changes in health since starting the diet, 3) assess perceived symptoms of nutritional deficiencies or other adverse effects, and 4) evaluate the satisfaction and acceptance of consuming a carnivore diet.
Participants and enrollment
Respondents were recruited from open social media communities Inclusion criteria were age ≥ 18 y and consumption of a carnivore diet for ≥6 mo by self-report. Data collection occurred during the period of the COVID-19 pandemic when most people were in lockdown.
Of an initial 3883 respondents, a total of 2029 (52%) respondents were eligible and willing to participate and provided sufficient information to be included in the study.
Data collection and treatment
Survey instruments
Survey questions were developed in consultation with members of the carnivore diet community and addressed several domains: 1) current intake frequency of main food groups and relevant food items, as well as food preparation and related considerations; 2) chronic medical conditions and medication use, anthropometric and laboratory data, perceived health and well-being, and perceived symptoms of nutritional deficiencies or other adverse effects—including in the present and before starting the diet; 3) diet satisfaction and social support; and 4) sociodemographic data. Multiple-choice questions were used to solicit specific habits, reasons for choosing the diet, medical conditions, and medication intake. Modified Likert scales were used to estimate the frequency of intake of prespecified food categories; satisfaction; and changes in health, well-being, chronic conditions, and symptoms. Highest educational attainment was categorized as primary (primary school or less), secondary (secondary school, including high school), postsecondary [intermediate between secondary and university (e.g., some college and technical training)], or tertiary (completed college, university, graduate school, or equivalent). Participants were asked to specify their income category as lower, middle, or upper. Race and ethnicity were self-reported with multiple-choice and free-text options. Self-reported anthropometric and laboratory data were collected for the following timeframes: Prior: within 1 and 5 y before starting the diet, respectively; Present: within a year of taking the survey and ≥3 mo after starting the carnivore diet. Participants were asked to specify source of anthropometrics as clinician or self-measured, and data were prioritized in that order.
Units of measure
To account for the international background of people within the social media communities, respondents were able to select among unit systems (metric, imperial, international system of units, conventional); data were collected accordingly and converted to metric and conventional units.
Calculated variables
Time on the diet and timing of anthropometric and laboratory data were calculated with reported dates and the survey date. Respondents were designated as having diabetes if they reported using the carnivore diet as a way to manage or reverse diabetes, if they had ever been prescribed any oral or injectable diabetes medications, or if they reported an HbA1c ≥6.5%.
Results
Participants
Most respondents were from the United States, Canada, Europe, or Australia; 67% were male; 83% were white and non-Hispanic; and 64% completed college or the equivalent. Income spanned all classes with 14% reporting low, 66% middle, and 20% high income. Seven women were pregnant and 10 were breastfeeding at median 12 mo [IQR: 9–18 mo] postpartum. The median [IQR] time following a carnivore diet was 14 mo [9–20 mo]; 93% of participants stated health reasons as their motivation for beginning the diet.
Red meat other than pork (e.g., beef, lamb, venison, buffalo, goat) was the most commonly consumed food, followed by eggs and non-milk dairy, whereas pork, poultry, and seafood were less frequently eaten. Weekly or more frequent consumption was reported for organ meat by 42%, and for non-milk dairy by 72%. Less than 10% of respondents consumed starchy vegetables, nonstarchy vegetables, fruits, or grains more often than once monthly, and 37% reported no use of any vitamin supplements. Use of other over-the-counter supplements (e.g., dietary, herbal, digestive enzymes, antioxidants) was denied by 75%. Alcohol was rarely consumed, with 63% reporting frequency of less than once a month or never. More than 50% of participants drank coffee at least daily. In contrast to the typical Western/Standard American diets, few individuals following the carnivore diet reported consuming fast foods.
Frequency of making exceptions from the carnivore diet.
Most participants reported eating 1–3 times daily (differentiation between meals and snacks was not queried), including 16% three times per day, 64% twice per day, and 17% once per day. Generally, more participants reported choosing cuts of meat with high (61%) or moderate (37%) fat content as opposed to lean cuts (2%). Seventy-six percent reported a preference for consuming meat at raw, rare, or medium-rare doneness. Intention to achieve nutritional ketosis was reported by 41%, among whom 41% monitored ketone concentrations; 56% intended to achieve a medium or high amount of salt intake, as commonly recommended in the setting of low-carbohydrate diets that are associated with increased natriuresis (36). Additional dietary data are available in Supplemental Table 3.
Perceived health-related outcomes
Participants reported improvements in chronic medical conditions, general health, and aspects of well-being such as energy, sleep, strength, endurance, mental clarity, memory, and focus (Figure 1). Table 3 lists the prevalence of specific medical conditions and changes in their severity. Although most queried medical conditions improved with the diet, lipid abnormalities were variably affected: 56% of participants reported resolution or improvement, 18% stability, and 27% new occurrence or worsening. Ophthalmologic conditions were improved or unchanged with equal frequency.
Reported changes in health status. Participants were asked to rate their current overall health and well-being on a 3-point scale as better (light gray bars), unchanged (dark gray), or worse (black) compared with the time before starting the carnivore diet. Percentage of respondents is given.
TABLE 3
Self-reported prevalence of and changes in chronic conditions and medication usage1
Table 4 and Supplemental Figure 1 summarize changes in anthropometrics and laboratory studies. Median [IQR] BMI decreased from 27.2 [23.5–31.9] to 24.3 [22.1–27.0]. As observed with other diets low in carbohydrate, TC and LDL-cholesterol were markedly elevated, whereas HDL-cholesterol and TG were in an optimal range. The Present ratio of TG to HDL-cholesterol was 1.0 [IQR: 0.7–1.5]. CRP and GGT decreased, and other liver enzymes, Cr, and HbA1c were unchanged from pre-diet to current. Coronary artery calcium score was low at Prior (2; IQR: 0–132) and Present (0; IQR: 0–27) among the few respondents reporting this value.
TABLE 4
Self-reported current and prediet anthropometrics and laboratory studies1
Among the 262 respondents with type 1 diabetes mellitus or type 2 diabetes mellitus (T2DM), prior BMI, HbA1c, and TG were higher than among those without diabetes.Respondents with diabetes experienced relatively large median [IQR] reductions in BMI (4.3 [1.4–7.2]) and HbA1c (−0.4% [0% to 1.7%]) (Supplemental Table 4). Diabetes medication use was significantly reduced. All respondents with diabetes discontinued noninsulin injection agents, 84% discontinued oral medications, and 92% of participants with T2DM discontinued insulin (Table 3).
Reported prevalence of adverse effects or symptoms consistent with nutritional deficiency was generally low, as shown in Supplemental Table 1, and commonly preceded the diet. New or worsened diarrhea occurred in 5.5%, constipation in 3.1%, weight gain in 2.3%, muscle cramps in 4.0%, hair loss or thinning in 1.9%, insomnia in 1.7%, dry skin in 1.4%, itchiness in 1.1%, heart rate changes in 1.1%, brittle fingernails in 1.0%, and menstrual irregularity in 1.0%. Worsening or incidence of any of the other assessed symptoms occurred in <1% of participants. Prevalence and incidence of symptoms were not increased compared with the overall group in participants who denied intake of vitamin supplements or denied consuming organ meat or dairy.
Satisfaction and support
Participants reported high levels of overall satisfaction with the diet (Supplemental Table 5). The majority perceived no impact on their social life, and neutral or positive supportiveness from social contacts. Medical providers were perceived as neutral, supportive, and unsupportive by generally similar proportions.
Discussion
In this social media–based survey, a self-selected group of adults consuming a carnivore diet for ≥6 mo reported perceived good health status, perceived absence of symptoms of nutritional deficiencies, and high satisfaction with this eating pattern. To our knowledge, this is the first modern report on a large group of people habitually consuming few plant foods, a dietary pattern broadly considered incompatible with good health.
Weight loss and other health benefits were most frequently indicated as the motivation for adoption of a carnivore diet. In accordance with this possibility, respondents reported substantial BMI reduction and improvements in physical and mental well-being, overall health, and numerous chronic medical conditions.Respondents with diabetes reported special benefit, including greater weight loss than the overall group, and marked reductions in diabetes medication usage and HbA1c—notable findings in view of the generally low success of lifestyle interventions for obesity and diabetes (37, 38). Although we did not formally assess macronutrient intake, carbohydrate content in meat and other animal-based foods is minimal, and inherent limits to protein intake exist. Both ancestral data (39) and self-reported preference of fatty cuts of meat in our survey suggest high fat intake with the carnivore diet. As such, the macronutrient composition of a carnivore diet would likely correspond to other very-low-carbohydrate diets (e.g., ketogenic, Atkins). For this reason, studies of these diets may provide relevant comparisons. In meta-analyses of trials for T2DM, low- compared with high-carbohydrate diets produced greater weight loss (40–42), lower HbA1c (40–46), and reduction in usage of glucose-lowering medications (41, 43, 45, 46), consistent with our observations. Although general dietary adherence and glycemic effects diminish over time (47), the findings of 1 recent nonrandomized trial suggest that a very-low-carbohydrate diet may be sustainable and efficacious when combined with high-intensity individual support (48).
Consistent with other low-carbohydrate diet studies (40–45), respondents reported a mixed blood lipid pattern: LDL-cholesterol, a major conventional cardiovascular disease risk factor, was markedly elevated whereas HDL-cholesterol and TG were favorable. However, LDL-cholesterol elevation, when associated with low TG, may reflect large, buoyant lipoprotein particles, possibly comprising a relatively low-risk subtype (49). Indeed, the low ratio of TG to HDL-cholesterol is suggestive of high insulin sensitivity and good cardiometabolic health (50). However, it is unclear whether this apparent benefit of the diet, together with the reported weight reduction and improved glycemic control (in the subset with diabetes), would counterbalance or outweigh any increased risk from LDL-cholesterol elevation. For individuals with a more extreme LDL-cholesterol response, drug treatment could be considered—an option that is generally more effective and better tolerated than drug treatment of insulin-resistance dyslipidemia.
Beyond macronutrient composition, elimination of allergenic, inflammatory, or other food components may provide potential health benefits to individuals following a carnivore diet. Food allergies and sensitivities are common, and predominantly related to plant foods (51). Some plant chemicals may produce adverse effects through other mechanisms, such as lecithin in beans, cyanogenic glycosides in certain seeds, and glycoalkaloids in potatoes. Indeed, >50% of survey participants started the carnivore diet to improve allergic, skin, or autoimmune conditions, or digestive health, and many reported improvements in inflammatory conditions and related symptoms. Conversely, dietary intake may be low for vitamins that are typically derived from plant foods (e.g., fruits, vegetables, nuts, seeds, and grains) or from nutritional fortification of staple foods (e.g., milk, juices, cereals, pastas, and other grain products) (52, 53). In addition, often unquantified phytochemicals (e.g., polyphenols, alkylresorcinols, phytosterols) are largely absent from the diet. Although these phytochemicals do not have DRIs, they have been linked to cardiometabolic benefits (54, 55). In people who eat meat only with exclusion of dairy (∼30% in this survey), calcium intake might also be low, as illustrated by the low intake and negative calcium balance in 2 Arctic explorers (28). Although essential nutrients can presumably be derived in sufficient amounts from animal foods (34), they are present in less commonly consumed parts of the animal, such as fat and organ meats (vitamins A and D), or bone (calcium), or may be reduced during food preparation (vitamin C) (34). Vitamin C is of particular interest, because meats are not formally considered a good source of vitamin C (i.e., they contain <10% of the DRI per serving) (56). Typical symptoms of deficiencies in these vitamins would include dermatological, cognitive, or neurological symptoms, as listed in Supplemental Table 1. A worsening or new presentation of these symptoms was reported in <2% of survey participants, whereas the majority of participants reported improvements, resolution, or no change—regardless of intake of vitamins, organ meat, or dairy. Given the self-reported nature of these findings, it remains unclear whether clinical or subclinical symptoms of nutrient deficiency are present. Research is needed to clarify the absence of perceived symptoms of nutrient deficiencies and the underlying biochemical processes that govern nutrient needs with the long-term consumption of a carnivore diet. It is possible that requirements for some micronutrients may be lower than those established in DRIs for the general population (57), related to remodeling of the gut microbiome, whole-body metabolism, and nutrient utilization in the setting of a low-carbohydrate carnivore diet, analogous to observations with a vegan diet (58).
Respondents reported high levels of satisfaction, and little social impact, from following a carnivore diet. Notably, medical providers were perceived as supportive, neutral, or unsupportive at generally similar proportions despite the discrepancy of the carnivore diets from dietary guidelines. Whereas meat is more expensive than grains and starchy foods, it may be less expensive on a caloric basis, depending on location and specific comparisons, than fresh fruits and nonstarchy vegetables (59), and cost may be in addition offset by decreased expenditure for diabetes and other medications. Our respondents spanned low to high income classes, suggesting against major financial barriers to the diet.
Our study does not address several important concerns related to consumption of an animal-based diet. Intensive animal production, typically with use of commodity grains and soy for feed, causes significant environmental harms and raises ethical issues about animal treatment. These concerns may be mitigated, to some degree, with integrated, pasture-based agricultural systems (60) and other interventions, such as the use of algal feed additives to reduce greenhouse gas production (61, 62). For context, industrial-scale, commodity grain monoculture may also cause substantial environmental impacts and loss of wildlife.
These findings must be interpreted cautiously in view of several major design limitations. Our survey assessed the perception of individuals following a carnivore diet and did not objectively assess diet, nutrient status, health-related outcomes, or confounding health-associated behaviors; and no physiological or biochemical measurements were obtained. These self-reported data are prone to recall and reporting bias, especially for the prediet information. Specifically, participants may have started the diet during a time of poor health and perceived subsequent regression to the mean as a benefit of the diet and being online community members may have resulted in over-reporting of adherence and perceived beneficial effects. Because no validated instruments are available to assess food intake frequency in a carnivore population, we used modified Likert scales. We did not assess portion size or other quantitative intake characteristics, nor did we use other dietary instruments for a more detailed characterization of the diet; these comprise topics of future investigations. Finally, the generalizability of the findings is unknown owing to the existence of selection bias, because individuals who experienced adverse effects or lack of health benefits are likely to have abandoned the diet and would therefore not have been captured in this survey. Adults adhering to a carnivore diet and responding to this online survey represent a special subpopulation with high levels of motivation and other health-related behaviors (e.g., physical activity, consumption of relatively whole, unprocessed foods). Therefore, respondents likely differ from the general population in ways that could influence the effectiveness, practicality, and safety of a carnivore diet. Related to this point, we did not obtain detailed information on diet and lifestyle habits before beginning a carnivore diet.
Our study reports on a large group of participants following a carnivore diet, with perceived health benefits and absence of symptoms consistent with nutritional deficiencies, providing insights into a poorly characterized dietary approach. However, the data are limited by several major design limitations inherent to the survey design. A clearer understanding of the long-term safety and benefits of a carnivore diet, exact dietary habits of people following this diet, and the generalizability of our findings, must await additional research.
Mortality Reduced With Adherence to Low-Carb Diet in Type 2 Diabetes
Mar 24, 2023
Lower mortality seen with increases in total, vegetable, and healthy low-carbohydrate diet score
By Elana Gotkine HealthDay Reporter
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FRIDAY, March 24, 2023 (HealthDay News) — For individuals with incident type 2 diabetes (T2D), a greater adherence to low-carbohydrate diet (LCD) patterns is associated with lower mortality, according to a study published online Feb. 14 in Diabetes Care.
Yang Hu, Ph.D., from the Harvard T.H. Chan School of Public Health in Boston, and colleagues calculated an overall total LCD score (TLCDS) among participants with incident diabetes identified in the Nurses’ Health Study and Health Professionals Follow-up Study. Vegetable (VLCDS), animal (ALCDS), healthy (HLCDS), and unhealthy LCDS (ULCDS) were also derived.
The researchers documented 4,595 deaths, of which 1,389 cases were attributable to cardiovascular disease (CVD) and 881 to cancer among 10,101 incident T2D cases, contributing 139,407 person-years of follow-up. Per each 10-point increment of postdiagnosis LCDS, the pooled multivariable-adjusted hazard ratios for total mortality were 0.87, 0.76, and 0.78 for TLCDS, VLCDS, and HLCDS, respectively. Significantly lower CVD and cancer mortality was seen in association with VLCDS and HLCDS. From the prediagnosis to postdiagnosis period, each 10-point increase in TLCDS, VLCDS, and HLCDS correlated with 12, 25, and 25 percent lower total mortality, respectively. For ALCDS and ULCDS, no significant associations were seen.
“Our findings provide support for the current recommendations of carbohydrate restrictions for T2D management and highlight the importance of the quality and food sources of macronutrients when assessing the health benefits of LCD,” the authors write.
Adapted from Medscape, What do we know about intermittent fasting by Carla Martinez Nov 28 2022
A session was dedicated to intermittent fasting at the 63rd Congress of the Spanish Society of Endocrinology.
In animal studies it has been shown that the same number of calories consumed in the morning result in greater weight loss/less fat deposition compared to when the same number of calories are consumed in the late afternoon or evening. Results in humans are less consistent though. My comment: perhaps because they watch television and have well stocked cupboards and fridges!
In humans who ate late, they reported twice as much hunger as the early eaters and energy expenditure and body temperature both reduced by 5%. Thus early eating seems to be more favourable.
Intermittent fasting regimes can very greatly in the window of opportunity allowed for feeding. Researchers found that being consistent with whatever schedule they followed resulted in reduced body weight, an improvement in metabolic efficiency, sleep duration and sleep quality, cardiovascular health, level of mood and quality of life. My comment: so many of us work variable shifts or have different wake and sleep times, feeding times and exercise patternson work days compared to off days.
Caloric restriction with a generous ten hour eating window resulted in weight, blood pressure and lipid improvements in people who had metabolic syndrome. Even in healthy subjects such as firemen who worked 24 hour shifts, limiting food intake to ten hours resulted in a reduction in HbA1c, LDL and diastolic blood pressure.
Dr Labayen is working on the Extreme Project which is testing obese people from Navarra and Grenada in Spain. There are 200 subjects, evenly spread between men and women, and they are advised to follow a Mediterranean diet and consume all their food within an 8 hour eating window. They are divided into early eaters, late eaters and free choice of eating window eaters. How easy the diet is to maintain and its effectiveness on body measurements and any side effects are being measured.
So far there have been fewer side effects than expected with night time hypoglycaemia more pronounced in the early eating group. There is more fat and muscle loss in the time restricted eating subjects compared to a control group who are not restricting their eating time, and the window time has not made any difference. Cardiovascular factor improvement seems to be the most noticeable effects.
Rafael de Cabo PhD, on the other hand primarily works with animals, particularly monkeys and mice. Perhaps, as these animals are not free to cheat on their diet, the effects have shown to be much better than in humans. Fasting has been shown in animals to improve cardiovascular disease, diabetes, cancer, and neurodegenerative disorders. A smaller eating window produces more positive effects than a larger window. Circadian rhythms improve, they eat fewer calories overall, weight and body fat reduces, blood pressure, oxidative stress, inflammation, and arteriosclerosis all are reduced. Hunger is also reduced. These effects occur whether the animals are obese or not. The difficulty is transferring these results to the general public. Currently there are at least 50 human trials underway with increasingly larger cohorts and different forms of intermittent fasting are tried out.
After considerable number crunching a low carb colleague has come to the very reasonable conclusion that the worst food in the world for weight gain is the fried potato in its several incarnations.
In the USA French Fries are what we in the UK call Chips. In the USA Chips are what we in the UK call Crisps.
These are ubiquitous and difficult to avoid particularly if you eat in fast food restaurants. Even if you order a sandwich you may be given a side order of chips or crisps.
Tucker explains that the vegetable and seed oils that these items are fried in play havoc with the appetite control centres of your brain. This article serves as a reminder, since we are all still at least trying to keep to our New Year’s Resolutions, why it would be better to avoid having them on your plate or hand in the first place. And just the one or two….who are you kidding?
Adapted from Diabetes in Control Sept 18 2021: Effects of earlier dinner times on glycaemic control by Andy Dao, Pharm D candidate, University of South Florida.
Growing up you may have heard from your family that eating close to bedtime isn’t a good idea. Eating later has indeed been shown to cause weight gain and metabolic dysfunction. Type 2 diabetes develops 10% more commonly in those who work shifts for instance. It is though that hormonal disruption of the circadian rhythm is the problem.
A recent study looked at how blood sugars were affected by eating earlier than 6pm or after 9pm over the whole 24 hour day. Adults over 20 wore blood sugar monitors over three days in this experiment. They were assigned to have their last meal of the day by 6pm or after 9pm. They had to eat or drink nothing but water after this meal. They were given identical meals three times a day. How they felt, what exercise they took and how well they slept were all assessed.
12 subjects completed the tests. Each group were of comparable height, weight and BMI.
There were significant reductions in blood sugar levels in the early diners in mean blood sugars throughout the whole day, night and early morning. Post prandial levels were also better in the evening for the early diners compared to the late diners but not for breakfast and lunch post prandial levels which were the same regardless of the evening mealtime.
The early diners did report more hunger and capacity to eat in the evenings than the later diners. There was no difference in sleep or physical activity.
So, if you do eat earlier, you can expect improved blood sugars all day long, and perhaps less likelihood of getting diabetes. The downside is more evening hunger. This study was done in healthy non-diabetic people and it would be interesting to see what the results in diabetic subjects would show.
Comment: Sitting down at 5 to 5.30 pm just wouldn’t work well for me, yet this is what we did in my childhood, and we didn’t eat snacks in front of the television after this. In my own house we have dinner at 7.30pm. This however is because I didn’t usually get home before 6.30 pm or even 7pm for many years so an earlier mealtime was not possible for me. I also tend to watch television from 8 pm for about 40 minutes or so before bath and bed. I couldn’t abide eating after 9pm as a regular thing, yet this is very common in Italy. I do think that I would be reaching for the oatcakes and cheese or more if I was in front of the television having eaten at 6pm.
Food Insight have published a survey of just over a thousand young adults aged 18 to 34 to question them about their dietary habits over the previous year. The study was published in 2018.
At that time a third were following some sort of diet. 16% were following some sort of low carb diet. The most frequent eating pattern was intermittent fasting coming in at 10% of those questioned.
In order of frequency the dietary patterns were:
Intermittent fasting, Paleo (10%) Gluten free, Low carb, Mediterranean, Whole 30, High protein, Vegetarian or Vegan (about 5%), Weight loss plan, Cleanse, DASH diet, Ketogenic or high fat diet, and other.
My comment: my personal diet is a mixture of Gluten fee, Low carb, Mediterranean, High Protein and High fat so I can see that there is certainly room for difficulty in assigning your diet a category. There seems to be a lot of publicity over Vegan and Vegetarian diets and I was surprised that there were not more young people on these. I would imagine that it would depend where the sample was from and other demographic information.
Adapted from Antvorskov JC et al. Association between maternal gluten intake and type one diabetes in offspring. BMJ 22 September 2018
This research was based on a study of Danish women’s food frequency questionnaires completed 25 weeks after their first pregnancies ended. The incidence of diabetes in the children was then noted from January 1996 till May 2016 from the Danish Registry of Childhood and Adolescent Diabetes. After certain exclusions had been made over 63,500 were analysed.
The mean gluten intake per day was 13g ranging from 7g to more than 20g per day.
The incidence of diabetes in the child increased proportionately according to gluten intake. The women who had 20g or more intake had double the type one diabetes in their offspring compared to those who ate 7g or less.
As type one diabetes has risen seemingly inexplicably over the last few decades, there has been a lot of consideration into possible environmental triggers. Gluten is a storage protein found in wheat, rye and barley. In animal studies, a wheat free diet in the mother has been found to dramatically reduce the incidence of diabetes in the child.
It has been suggested that gluten can affect gut permeability, gut microbiotica and cause low grade inflammation.
Although there is this association between gluten and type one diabetes it could be that other factors, for example the advanced glycation products from the baking process, that are to blame. Unwanted additives to grain could also be a factor eg mycotoxins, heavy metals, pesticides and fertilisers.
Mothers who eat a lot of gluten may similarly feed their children a lot of gluten. They also may pass gliadin from wheat into the breast milk.
Although this research suggests that high amounts of gluten may be problematic in pregnancy, further research will need to be done before dietary recommendations are likely to be changed.
There is a hypothesis gaining ground which is that the omega 6 fats in vegetable oil disrupt metabolism and promote fat gain way beyond their simple caloric value.
Dr Michael Eades explains the epidemiology which suggests that this is the case and then the biochemistry which provides a plausible explanation.
This video is 45 minutes long and is quite technical in parts.
Julie Devinsky1 
Diabetes Diet 
