Review of the plant-based nutrition and lifestyle medicine news January 2026
The new year always brings renewed focus on healthy habits. This month I provide a reminder of how healthy habits can support better health for all life stages.
The year kicked off with the highly anticipated release of the Dietary Guidelines for Americans (DGA). These were always going to be controversial since it was known that the recommendations of the Dietary Guidelines Advisory Committee had been thrown out and replaced by a rather non-transparent process. I have written a separate in-depth review. Needless to say, ideology and industry influence has replaced evidence-based recommendations.
At the same time, the US New and World Report has published their annual analysis of the best diets for various health conditions, as recommended by a panel of experts. In contrast to the DGAs, all recommended diets have a focus on nutrient-dense, fibre-rich plant-based foods.
Going forwards, it is going to be difficult to assess the impact of dietary guidelines on health outcomes with so many people using GLP1 agonists for weight loss and their potential positive impacts for other chronic conditions. However, diet and lifestyle support will remain fundamental for the success of these therapies as demonstrated by the next two papers.
Nutritional and lifestyle supportive care recommendations for management of obesity with GLP-1 – based therapies
This expert consensus statement addresses a rapidly evolving area of obesity care: how best to support people using GLP-1–based therapies such as liraglutide, semaglutide and tirzepatide with appropriate nutrition and lifestyle interventions. Recognising that these drugs can produce substantial weight loss but are frequently accompanied by gastrointestinal side effects, nutritional inadequacy and high discontinuation rates, the authors convened an international, multidisciplinary panel to develop practical recommendations using a modified Delphi process.
Drawing on a broad scoping review of the literature published since the introduction of semaglutide for weight management, alongside established obesity and nutrition guidelines and extensive clinical experience, the panel agreed on 52 consensus statements covering the full patient journey. These span preparation before starting therapy, management during the active weight-loss phase, longer-term weight maintenance, and strategies to mitigate harm if treatment is discontinued. Central to the guidance is the recognition that GLP-1–based therapies should not be viewed as stand-alone solutions, but as part of a comprehensive, individualised approach that prioritises nutritional adequacy, physical activity, preservation of lean body mass and long-term behavioural support.
The statement emphasises that people living with obesity are often at baseline risk of micronutrient deficiencies due to poor diet quality, and that the profound appetite suppression induced by GLP-1 therapies may exacerbate these risks. Ensuring adequate protein intake, sufficient dietary fibre, hydration and micronutrient sufficiency is therefore presented as fundamental, not optional. The authors stress the importance of regular monitoring to avoid excessive or overly rapid weight loss, which may compromise muscle mass, bone health and overall nutritional status, particularly in older adults or those with sarcopenic obesity.
Physical activity is positioned as a critical co-therapy, with a strong consensus around combining aerobic exercise with resistance training to support cardiometabolic health and mitigate loss of lean mass during weight loss. The guidance also provides pragmatic advice on managing common gastrointestinal side effects through dose adjustment, meal timing, food choices and hydration, reinforcing that these symptoms are usually transient and manageable without undermining weight-loss efficacy.
Importantly, the paper highlights the reality that many people discontinue GLP-1–based therapies within a year, often due to cost or access rather than clinical choice. In this context, the authors underscore the high risk of weight regain after cessation and the need for structured nutritional and lifestyle support to reduce rebound weight gain. Throughout, there is a consistent call for care that is non-judgemental, stigma-free and grounded in shared decision-making, ideally involving registered dietitians and multidisciplinary teams.
Overall, this consensus statement does not claim to be underpinned by a strong body of direct trial evidence, and the authors are transparent about this limitation. Instead, it offers a thoughtful, clinically grounded framework to help healthcare professionals integrate nutrition and lifestyle medicine into the use of powerful new pharmacological tools, while clearly signalling the urgent need for better evidence on optimal dietary patterns, long-term nutritional consequences and strategies to sustain health gains beyond medication use.
Weight regain after cessation of medication for weight management
This systematic review and meta-analysis pooled data from 37 studies involving more than 9,000 adults treated with weight-management medications, including modern incretin-based therapies such as semaglutide and tirzepatide, as well as older pharmacological agents. The authors sought to quantify what happens to body weight after these medications are stopped, a question of growing importance as incretin therapies become widely used for obesity treatment.
The central finding is that weight loss achieved during active pharmacotherapy is typically followed by substantial weight regain once medication is discontinued. On average, people regained weight at a rate of approximately 0.4 kg per month after stopping treatment, and modelling from the combined studies projected that most individuals returned to their pre-treatment weight within about 1.7 years of cessation. The pattern was similar for both newer GLP-1 receptor agonists and older weight-loss drugs, although the absolute amount of weight regained tended to reflect the amount lost during therapy.
Importantly, the analysis also found that cardiometabolic markers such as blood glucose and blood pressure tended to revert toward baseline alongside body weight, with projected return to pre-treatment levels within about 1.4 years after stopping medication. This suggests that the physiological benefits accrued during drug use are not sustained in the absence of ongoing treatment or concurrent lifestyle support.
When compared with traditional behavioural weight-management programmes involving diet and physical activity, the rate of weight regain after stopping pharmacotherapy was almost four times faster, even though behavioural programmes typically produce smaller initial weight losses. This highlights that the phenomenon of weight regain is not unique to drugs, it reflects the fundamental biology of energy balance, but that medications do not intrinsically alter the body’s homeostatic responses in a lasting way once they are withdrawn.
The authors and subsequent commentators emphasise that these findings do not undermine the value of weight-loss medications for appropriate patients, but they do caution against viewing them as a standalone long-term solution. Instead, the data underscore the chronic, relapsing nature of obesity and the need for integrated, ongoing strategies, including attention to nutrition, physical activity, behavioural support and metabolic adaptation, to support durable health outcomes beyond the period of pharmacotherapy.
Which foods support a healthy body weight?
This comprehensive umbrella review synthesises the highest level of available evidence on how different food groups relate to the risk of developing overweight and obesity, drawing together data from 13 systematic reviews and meta-analyses, most of them based on large prospective cohort studies.
By focusing on food groups rather than individual nutrients, the authors provide a clear and policy-relevant picture of which foods are consistently associated with long-term weight gain and which appear protective.
Across the evidence base, foods most consistently associated with a lower risk of overweight and obesity are whole grains, legumes, nuts and fruits. Higher intakes of these foods were associated with reduced risk both in high-versus-low comparisons and, for several groups, in dose-response analyses. Whole grains and fruits in particular showed a largely linear relationship, with progressively higher intakes associated with lower risk across the observed range. Legumes, although supported by fewer studies, also showed a protective association, aligning with their role as fibre-rich, low-energy-density staple foods. Nut consumption was associated with lower risk of overweight and obesity despite their energy density, with the strongest associations seen at moderate intakes, suggesting that satiety effects and displacement of less healthy foods may be more important than calorie content alone.
Vegetables showed a more nuanced relationship. While many individual studies suggested benefit, the pooled results did not reach statistical significance in all analyses, and non-linear dose-response curves suggested that moderate intakes were associated with the lowest risk. This likely reflects methodological limitations, including measurement error and limited variability in vegetable intake within many populations, rather than an absence of biological effect.
In contrast, foods most clearly associated with weight gain and higher risk of overweight and obesity were sugar-sweetened beverages and red meat. Sugar-sweetened beverages showed one of the most consistent and robust associations in the review, with higher consumption linked to increased risk in both high-versus-low and per-serving analyses. This strengthens the causal inference that liquid sugars contribute to excess energy intake and weight gain. Red meat consumption was also associated with increased risk, particularly in high-versus-low comparisons, likely reflecting its energy density, saturated fat content and the broader dietary patterns in which it is typically consumed.
Refined grains and processed meats showed trends towards increased risk, but the associations were weaker and in some cases did not reach statistical significance, partly due to higher heterogeneity and lower quality of the underlying evidence. Total dairy intake was not consistently associated with either weight gain or protection, with mixed findings depending on dose and product type, highlighting the limitations of grouping diverse foods under a single category.
Taken together, the findings reinforce a pattern that is now familiar across nutrition research: diets built around minimally processed plant foods are associated with better weight outcomes over time, while diets characterised by sugary drinks and higher intakes of red and processed meats are associated with weight gain. Importantly, these associations emerge from long-term observational data rather than short-term weight-loss trials, providing support to their relevance for prevention. In the context of current debates about obesity management, including the rapid uptake of pharmacological therapies, this review serves as a reminder that food patterns remain central to population weight trajectories, and that the foods associated with healthier body weight are, by and large, the same foods associated with lower risk of chronic disease and lower environmental impact.
Minimal and optimal lifestyle habits for improving all-cause mortality
This large prospective analysis from the UK Biobank offers a timely and important reminder that health behaviours do not operate in isolation, and that it is their interaction which matters most. Drawing on wearable-derived data for sleep and physical activity alongside a diet quality score derived from dietary questionnaires, researchers examined how combined variations in sleep, physical activity and nutrition relate to all-cause mortality over a median follow-up of just over eight years. What distinguishes this study is not simply its scale, but its explicit attempt to quantify the minimum combined changes across these behaviours associated with meaningful reductions in mortality risk, rather than focusing only on ideal or often unrealistic targets.
The findings are striking in their practicality. While optimal combinations of moderate sleep duration, higher levels of moderate-to-vigorous physical activity and better diet quality were associated with substantially lower mortality risk, the most clinically relevant message lies elsewhere. Very small, concurrent improvements across all three behaviours were associated with measurable benefits. An additional fifteen minutes of sleep per day, 1.6 minutes more of moderate-to-vigorous physical activity, and a modest improvement in diet quality ( 1/3 cup of cooked vegetables and 1.5 servings of fruit extra per day) were together associated with a 10% reduction in all-cause mortality. None of these changes, when considered in isolation, achieved the same effect. Diet quality in particular showed limited association with mortality unless accompanied by more favourable sleep and activity patterns, reinforcing the idea that nutrition cannot be meaningfully disentangled from the wider context of daily living.
Larger combined shifts were associated with progressively greater reductions in mortality risk. A pattern characterised by roughly an extra hour of sleep per day, around 12 minutes more physical activity, and more substantial improvements in diet quality was associated with a 50% lower risk of death during follow-up. At the upper end of the spectrum, the most favourable combination of sleep, physical activity and diet quality in this study was associated with a 64% per cent lower mortality risk compared with the least favourable pattern.
On a similar theme, it seems even small amounts of physical activity alone can reduce mortality. A large analysis published in the Lancet has shown that even a 5 minute increase in moderate to vigorous physical activity per day could reduce the risk of death by up to 10%, whilst reducing sedentary time by 30 minutes a day would provide additional benefits. Of course, more is better, and this new analysis in the BMJ shows that higher levels of physicial activity are associated with larger reductions in mortality with a greater variety of activities having independent additional benefits to just the total amount of activity.
Lifestyle interventions in pregnancy on gestational diabetes
This study shifts the focus earlier in the life course and into a period where prevention has implications not just for one individual, but for two generations. In this large individual participant data and network meta-analysis, the authors examined the effects of lifestyle interventions during pregnancy on the risk of gestational diabetes, drawing together data from multiple randomised trials to compare different approaches more robustly than has previously been possible.
What emerges clearly is that lifestyle interventions in pregnancy can reduce the risk of gestational diabetes, but that not all interventions are equally effective, and timing matters. Physical activity interventions appeared to be the most effective single intervention and so were interventions delivered in a group format.
The dietary components of effective interventions tended to emphasise overall diet quality rather than rigid macronutrient targets, aligning with broader evidence that dietary patterns matter more than individual nutrients. Prior studies have shown that plant-based dietary patterns are associated with a lower risk of gestational diabetes.
From a lifestyle medicine perspective, the findings reinforce the idea that pregnancy represents a window of opportunity for meaningful, supported behaviour change, but also a moment of vulnerability. Interventions that were supportive, structured and integrated into routine antenatal care were more likely to succeed than those that relied on individual motivation or compliance. The study also highlights a recurring challenge: while lifestyle interventions can reduce gestational diabetes risk, their implementation remains uneven, and access is often poorest for those who would benefit most.
The wider implications extend well beyond pregnancy itself. Gestational diabetes is a strong predictor of future type 2 diabetes and cardiometabolic disease for the mother, and of metabolic risk for the child. Reducing its incidence through achievable, non-stigmatising lifestyle interventions therefore represents a form of intergenerational prevention. Taken together with the broader lifestyle literature, this analysis strengthens the case for embedding nutrition and lifestyle medicine into standard antenatal care, not as an optional add-on, but as a core component of preventive health across the life course.
Dietary interventions and gut microbiota
This systematic review brings much-needed clarity to an area that has generated enormous interest but is often discussed in overly simplistic terms. Drawing together evidence from 80 controlled clinical trials, the authors examined how different dietary patterns influence the gut microbiota, allowing for a direct comparison between plant-based diets (including vegetarian and vegan) and a range of other commonly studied dietary interventions.
Across the body of evidence, plant-based dietary patterns consistently emerged as the most favourable for gut microbial diversity and function. Diets characterised by higher intakes of whole plant foods were associated with increased microbial richness, higher abundance of butyrate and anti-inflammatory bacteria. These changes are widely regarded as markers of a healthier gut ecosystem and are mechanistically linked to improved metabolic, immune and inflammatory outcomes. Additionally, a plant-based diet was associated with reduced triglycerides, total cholesterol, LDL cholesterol, and both fasting and postprandial glucose levels, along with reduced HbA1c levels indicative of improved blood glucose control.
Western-style, high fat and ketogenic diets stood out for their contrasting effects. Although some trials reported short-term changes in specific microbial taxa, these patterns were frequently accompanied by reductions in overall diversity and marked decreases in fibre-associated bacteria and short-chain fatty acid production. In addition, they showed adverse impacts on blood lipids, markers of inflammation and glucose regulation.
From a clinical and public health perspective, these findings strengthen the biological plausibility underpinning plant-based nutrition recommendations. They also help explain why plant-predominant dietary patterns are repeatedly associated with lower risk of cardiometabolic disease, certain cancers and all-cause mortality. The microbiome emerges not as a separate or fashionable add-on, but as a central mediator linking what we eat to long-term health. For lifestyle medicine, this reinforces a familiar but still under-appreciated message: diets built around a wide variety of whole plant foods support not only human physiology, but also the complex microbial ecosystems on which our health depends.
Lifestyle interventions for major depressive disorders – a consensus statement
This expert consensus statement from the American College of Lifestyle Medicine represents one of the most comprehensive attempts to date to formally integrate lifestyle medicine into the prevention and management of major depressive disorder. Using a rigorous modified Delphi process, a multidisciplinary panel of experts reviewed the existing evidence base and reached consensus on 71 statements covering assessment, diagnosis, and the six core pillars of lifestyle medicine: nutrition, physical activity, sleep, stress management, social connectedness, and avoidance of harmful substances.
At its core, the statement challenges the continued marginalisation of lifestyle interventions in mental health care. While acknowledging that pharmacological and psychological therapies remain important, the panel reached strong consensus that lifestyle interventions are foundational to the management of major depressive disorder, rather than optional adjuncts. Physical activity emerged as the intervention with the most robust and consistent evidence, with consensus that it can be used as a primary therapy for adults with mild depression and as an effective adjunct for moderate to severe disease. Notably, the strength of evidence for physical activity compares favourably with antidepressant medication, with substantially lower numbers needed to treat to achieve clinical benefit.
Nutrition and gut health feature prominently, reflecting a growing recognition of the diet–brain–microbiome axis. The panel reached consensus that whole-food, plant-predominant dietary patterns, including Mediterranean-style eating, are associated with lower risk of depression and improved outcomes in people with established disease. Diets high in fibre, polyphenols and minimally processed plant foods were consistently viewed as beneficial, while dietary patterns high in ultra-processed foods, saturated fat, refined carbohydrates and salt were associated with increased risk of major depressive disorder. Importantly, the statement explicitly notes insufficient evidence to support ketogenic or very low-carbohydrate diets for depression management, while highlighting well-documented adverse cardiovascular and metabolic effects associated with these patterns.
Sleep was identified as another critical pillar, with strong consensus that sleep quality, quantity and regularity directly influence depressive symptoms and long-term mental health outcomes. The panel emphasised the importance of assessing sleep routinely in people with depression, including screening for obstructive sleep apnoea, which is highly prevalent in this population. Cognitive behavioural therapy for insomnia, delivered either in person or digitally, was endorsed as an effective intervention that can improve both sleep and depressive symptoms.
The consensus statement also places considerable emphasis on stress, social connection and the wider environment. Loneliness, lack of social connectedness and chronic unregulated stress were all identified as significant risk factors for the development and persistence of depression. Social interventions, including peer support, group activities and community engagement, were viewed as effective components of care, while the panel clearly distinguished meaningful social connection from passive social media use, which does not confer the same mental health benefits. Substance use, including alcohol and cannabis, was consistently associated with higher prevalence of depression, anxiety and suicidal ideation, reinforcing the need to address these factors as part of comprehensive care.
Across all domains, the statement highlights that effective lifestyle intervention depends not only on what is recommended, but on how it is implemented. There was strong agreement that assessment of baseline lifestyle habits should be routine, that care should be trauma-informed and equity-focused, and that sustained behaviour change is more likely when interventions are integrated into daily life, supported by social networks and delivered through coordinated, multidisciplinary care. The authors are careful to position this work as a consensus statement rather than a formal clinical guideline, reflecting ongoing gaps in the evidence, but the message is nonetheless clear: lifestyle medicine offers powerful, evidence-based tools for improving mental health outcomes that remain underused in clinical practice.
There’s no such thing as climate-friendly beef
Food system transformation is urgently needed to meet our global nature and climate targets. Yet the meat and dairy industry continue to suggest that changes in farming practices can reduce the environmental harms associated with the production of animal-sourced foods.
This new analysis from the World Resources Institute makes it clear that claims of “low-emissions” or “net-zero” beef are, at present, more marketing than reality. When greenhouse gas emissions are counted across the full lifecycle, including methane from cows, feed production, land use change and deforestation, even the best available production methods reduce beef’s climate impact by only modest amounts. Even with improved practices, beef continues to emit far more greenhouse gases per unit of protein than most plant-based foods, and labels that tout sustainability often rely on questionable offsets rather than transparent, verifiable reductions in emissions. In practical terms, the only scalable way to reduce the climate burden associated with beef is through lower consumption and a shift toward more plant-predominant dietary patterns that are both healthier for people and markedly lower in carbon emissions.
See you back in February!
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