Binge eating: cause and cure

Adapted from: Ultra processed foods and binge eating: a retrospective observational study by Agnes Ayton MD et al. Nutrition 84 (2021) 111023 and Treating binge eating and food addiction symptoms with low-carbohydrate Ketogenic diets: a case series by Matthew Carmen et al. Journal of Eating Disorders (2020) 8:2.

In general ultra processed foods are high in sugars and fats and low in natural protein. They are considered to be not modified foods but formulations made mostly from substances derived from foods, many of them not normally used in culinary preparations, as well as additives. A series of processes are used to create the final product. Many ingredients including sugars are metabolically active and may have an addictive potential. Such foods include soft drinks, sweet or savoury packaged snacks, reconstituted meat products, pre-prepared frozen dishes and diet products.

Ultra processed foods have been gradually displacing unprocessed or minimally processed foods and freshly prepared meals. In the UK the percentage of foods eaten in this category ranges from 30-80% and the average is 56.8%. This has led to an increase in the amount of starches, sugars and fats, and a decrease in the amount of protein consumed. Increases in the amount of these foods consumed is linked to increasing rates of obesity and metabolic disorders. They seem to reduce satiety and stimulate overeating. People who are allowed to eat what they want end up eating more carbohydrate and fat but not protein. This results in widespread endocrine changes. Animal and human experiments show that ultra processed foods interact with various hormonal and neurobiological systems that affect food intake.

Responses to common foods vary from person to person and are influenced by such factors as insulin resistance, sleep, stress, exercise and the microbiome. These differences affect glucose tolerance and insulin sensitivity.

The detailed records of 73 people who had attended an eating disorders clinic in Oxford between 2017 and 2019 were examined retrospectively. Only 3 were men, the majority of patients being women.

Common ultra processed food items consumed included: breakfast cereals, diet yoghurt, diet drinks, biscuits, snack bars, cake, sandwiches, Quorn sausages, waffles, crisps, ready meals, pizza, ice cream, and doughnuts.

Eating patterns showed that while breakfast and snacks were commonly missed, most people ate lunch and dinner, and binge eating tended to occur more towards the evening. During the day most people chose foods low in fat and protein.

The foods consumed during binge eating were 100% ultra-processed such as chocolate, ice cream, crisps, sandwiches, biscuits, cakes, pizza, smoothies and doughnuts.

Meals were often missed during the day indicating that dietary restriction is shared between people with eating disorders regardless of the actual precise type.

A separate cross over study reported that patients did not notice a difference in palatability between normal and ultra processed foods, yet ate 500 k cals more a day on the ultra processed foods. The hunger hormone ghrelin, fasting glucose and insulin are all raised with ultra processed foods and the appetite suppressing hormone peptide tyrosine is reduced. Although fat and carbohydrate were increased in amount, protein intake remained the same suggesting that excess intake is driven by dilution of dietary protein.

Anorexia Nervosa is associated with increased insulin sensitivity while Bulimia Nervosa and Binge Eating Disorder are associated with insulin resistance. Indeed 30% of patients with BED had impaired glucose tolerance. It is possible that metabolic factors contribute to binge eating.

Overconsumption of food may also be driven by combinations of sugar and fat not found in nature and also non-nutritive sweeteners.

The nutrient sensing system plays a critical role in regulating striatal dopamine and reward. This is subconscious. The second conscious system influences food choices based on beliefs of healthfulness, cost and so on, which are heavily targeted by advertising and the food environment.

Patients with eating disorders choose diet products, which are actually often ultra processed, having the belief that these are healthier options, unaware of the metabolic and neurobiological effects that impair accurate sensing of nutrient content by the brain and result in uncontrollable eating during a binge episode.

The cavalry coming over the hill in all this could be the good old ketogenic diet.

Carmen et al from Stanford University reported on three patients aged 34, 54 and 63 whose average BMI was 43.5. They undertook a ketogenic diet consisting of 10% carbohydrate, 30% protein and 60% fat for 6 to 7 months. They all had binge eating and food addiction symptoms.

They were all pleased to report no major adverse effects on the diet and a significant reduction in binge eating episodes and food addiction symptoms such as cravings and lack of control. They also lost between 10 -24% of their body weight.

After the study finished, they all continued on the diet for 9-17 months and continued to have no recurrence of their original binge eating and cravings. In one patient with a pervasive low mood this also substantially improved.

Food addiction symptoms have been described as an addictive response to foods such as sweets and starches. These include much time spent obtaining food, feelings of withdrawal when off food, continued use despite adverse consequences, important activities reduced or given up, repeated unsuccessful attempts to stop, and eating more than intended.

Rates for food addiction are up to 42% for patients who are waiting on bariatric surgery. In people who have obesity the rates are 15 to 20%.

The ketogenic diet produces appetite suppression, lower hunger, greater satiety, greater fat burning, lower fat formation, more glucose being made in the liver and the increased thermic effect of proteins.

The patients were asked to keep to 20-30g of carbohydrate a day or less and to eat whole foods, not processed, including meat, seafood, nuts and eggs, 4 oz of hard cheese a day, 2 cups of assorted salad vegetables, cup of non starchy vegetables and low carb fruit. They were asked to not count calories and to eat till they felt full and then stop.

This small case series supports the feasibility of using a low carb ketogenic diet for patients presenting with obesity and self reported binge eating and food addiction symptoms.

Ketogenic diets can also be used for paediatric epilepsy, gastro oesophageal reflux, irritable bowel syndrome, and Crohn’s disease. Mental disorders such as bipolar disorder, psychosis and schizophrenia.