Adapted from The Lancet 19th May 2026

Is weight cycling clinically harmful?

Prof Faidon Magkos, PhD^a Send email to fma@nexs.ku.dk ∙ Prof Norbert Stefan, MD PhD^b,c,dAffiliations & NotesArticle Info

Publication History:

Published May 14, 2026

DOI: 10.1016/S2213-8587(26)00037-9 External LinkAlso available on ScienceDirect External Link

Copyright: © 2026 Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

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Summary

Worldwide, approximately half of the general population is actively attempting to lose weight.

However, weight loss is typically followed by substantial weight regain, often leading to repeated cycles of loss and gain of bodyweight. Weight cycling has been suggested to be metabolically harmful, in that it could lead to greater rebounds in fat mass and smaller regains in lean (muscle) mass, thereby promoting sarcopenia, lowering metabolic rate, and exacerbating obesity and its metabolic complications (eg, glucose intolerance).

In this Personal view, we critically evaluate evidence from studies in humans and animals investigating whether weight cycling has adverse effects on bodyweight, body composition, energy metabolism, and metabolic function. We also briefly discuss potential strategies to mitigate weight regain and its consequences.

Overall, the current evidence does not support a causal link between weight cycling per se and clinical harm in people with obesity.

Most of the adverse effects reported are likely circumstantial, possibly because of ageing, unintentional weight loss, reverse causality, earlier onset of obesity, repeated obesogenic exposures, or longer cumulative exposure to obesity.

Available evidence suggests that the benefits of intermittent weight reduction—such as improved metabolic markers, cardiovascular health, and quality of life—outweigh the potential risks associated with weight fluctuation.

Adapted from BMJ 21-28 March 2026

Throughout the UK, Accident and Emergency Departments are in crisis.

A survey by the Royal College of Emergency Medicine was sent a survey to their members in March.

51% of the 80 respondents said that their department was fairly or very unsafe and 28% said that their department was very or fairly safe.

88% said that overcrowding was a daily occurrence. 96% said overcrowding happened several days a week.

Meanwhile in Scotland, Fiona Hunter, the Vice President of the Scottish branch of the Royal College of Emergency Medicine. In 2024 the college showed that 818 excess deaths occurred due to long waits in Accident and Emergency Departments.

The Scottish Liberal Democrats analysis reported that in 2025 there were 871 deaths associated with a wait of 12 hours or more for hospital admission in Accident and Emergency Departments.

My comments: A lot of A and E attendees are people who would be better served by Primary Care than A and E. General Practitioners are under strain, and have limited appointments in weekday and out of hours services by allocating fixed appointments, instead of absorbing the work regardless of ability to provide good care. This is a way of coping and I don’t blame them. The result however, is ever overflowing A and E departments. I know that some areas have GPs on site in hospitals to deal with some patients but this doesn’t happen everywhere.

Adapted from BMJ 21-28 March 2026

Cancer death rates in the UK are their lowest level on record.

This level peaked in 1989 and is now 29%. About 250 in every 100,000 die from cancer each year. This is 11% lower than ten years ago.

Cervical cancer has shown the greatest fall in death rates. Deaths have fallen 75% in the last 50 years. Much of this is due to cervical screening programmes. The progress is likely to continue as there has been a great impact in cervical cancer prevention since the vaccination programme against HPV started in 2008.

Adapted from BMJ 18-25 April 2026

Firstborn children are known to outperform their later born siblings in adulthood regarding earning capacity and IQ. It has now been shown that these differences start really early in babyhood from research published in JAMA.

In Japan, 2,000 sibling pairs were tested regarding cognitive skills and developmental milestones. By six months of age, the older siblings outperformed the younger ones. Some of the differences evened out by the age of 12 months, but deficits in fine motor skills and personal-social areas persisted.

This difference however is paralleled by lower parental engagement for second born and subsequent children. Resources become diluted as families grow.

My comment: I do remember slacking off with my second son compared to my first. The first one got everything done by my Penelope Leitch book.

The second got warmer and more social baths, far fewer photographs taken, was able to decide his own bedtimes, decided when he was ready to get toilet trained, I found him trying to change his own nappy, and I didn’t bother trying to get him to eat vegetables or anything he didn’t immediately like. He also stayed on bottled milk far longer. He was able to get these himself out of the fridge. Unlike baby #1 I didn’t warm up the milk after one month of age and he took it chilled.

I hope my lack of diligence in one side of the equation gave me more time to spend talking to him and playing with him on the other. He did speak far later though.

They have both done very well in adulthood although the limited dietary intake persists. I do think the younger child had a better time of it with a more relaxed parenting style.

Adapted from BMJ 18-25 April 2026

A study published in Psychiatry indicates that cannabinoids don’t do much, if anything, for mental health improvement.

A systemic review of 54 clinical trials involving over 2,500 participants, showed no consistent benefit for anxiety, depression, or post traumatic stress disorder.

Limited evidence of benefit was seen in insomnia, Tourette’s syndrome and autistic spectrum disorder, but the study quality was low.

My comment: As a doctor I was aware that some patients got a benefit from cannabis/cannabinoids for chronic pain and multiple sclerosis. I’m also aware that some dogs are being given cannabinoids for various complaints and also been told that sometimes it makes a big difference.

Adapted from BMJ 18 -25 April 2026

Kengo Miyoshi, Assistant Professor, Tokyo states that to avoid weight regain with GLP-1 drugs, Japanese patients enter a programme of structured support to maximise the effectiveness of the intervention.

The drugs are regulated and are only given where there are obesity related co-morbidities and functional impairment. The drugs are only started after six months of lifestyle modification which includes dietary, exercise, psychological and behavioural modifications. These should be continued lifelong. At the six month point, GLP-1 drugs are prescribed but for a maximum of 68-72 weeks. The exit criteria is established at the outset. The continued support mitigates the “weight regain” effect.

Randomised controlled trials have shown that exercise makes a big difference to the effects of the drugs during and after GLP-1s are stopped. While on the drugs, exercise promotes greater fat loss, preservation of lean muscle mass, improved insulin sensitivity, increased cardiorespiratory fitness, and physical functioning. When the drugs are stopped, the preserved lean muscle mass, higher exercise expenditure and sustained physical activity lead to less fat regain. The metabolic improvements need to be supported by structured care long term. Obesity is after all a long term condition and needs to be supported as such.

Adapted from BMJ 21-28 February 2026

In a Norwegian cohort study of more than 1.3 million births, they found factors that both increased and decreased the chances of the baby developing multiple sclerosis in adulthood.

Increased risk of multiple sclerosis:

the mother has diabetes

the baby is born large for gestational age

No change in rate of multiple sclerosis:

baby born preterm

mother has hypertension or eclampsia

placental abruption occurence

Decreased risk of multiple sclerosis:

baby is born small for gestational age

Adapted from BMJ 21-28 Feb 2026

The relation between social media use and adolescent wellbeing may not be as simple and linear as many people believe.

In a large Australian cohort followed over three years, moderate after school social media use was associated with better wellbeing than either heavy use or none at all.

(JAMA Pediatr doi:10.1001/jamapediatrics.2025.5619).

Although heavy users were more likely to report low wellbeing in early adolescence, non-users had worse outcomes later on. The patterns varied by sex and age.

My comment: I understand that Australia is planning to ban smart phone use in schools and that some schools in the UK want this or are already doing this now.

Smart phones are little personalised computers that can be used as blood glucose monitors, with the right equipment, calculators, dictionaries, fact checkers, spelling checkers, payment systems, foreign language tutors, game consoles, alarm clocks, fitness checkers, social media hubs, weather forecasters, newspaper sources, bus and train timetables and purchases, and can enable family to keep in touch with their child and vice versa. I can easily see why they could be of real use to everyone and a loss to schoolchildren, particularly type one diabetics, who use them responsibly.

Unfortunately they can also be a source of harm, particularly regarding mental health, when online bullying occurs.

My children are now adults and small mobile phones were around when they were teenagers but since neither myself or my husband had smart phones we never considered getting them for our children. The iphone came out in the USA in 2007 and cost $495-$595 dollars. The only children who had smart phones were those children who came from disadvantaged homes, who were paid £30 a week to attend school. The more affluent working and middle class kids didn’t have them. The Freestyle Libre hadn’t yet been invented and wouldn’t be for a considerable time.

I can see that a blanket ban on smartphones would have disadvantages. If I had had one as a teenager, I can see that it would have been marvellous for all school work, homework, getting to school and even getting up in the morning. The single subject that it would have boosted enormously was language learning. Struggling with a difficult mathematical or science topic? Calculus springs to mind. You tube video could probably explain it much better than some teachers. Although I think blanket bans go too far, I’m not sure what rules would need to be put in place to prevent misuse of social media and how these could be enforced. It’s a problem that I avoided but something that at least some of you will need to decide now or in the future.