Delegates at the British Nutrition Foundation’s Conference, The What, How and When of Weight Loss, heard from experts spanning key areas of scientific research into weight management, that the ‘obesogenic environment’ we live in and the biological resistance of the body to losing weight can confound people’s efforts to get to and maintain a healthy weight.
Dr Wendy Hall, Reader in Nutritional Sciences at King’s College LondonDr Wendy Hall, Reader in Nutritional Sciences at King’s College London, who chaired the conference, explained how sleep is one of the ‘obesogenic environment’ factors that could be linked to weight loss and management. She said: “Our research into the potential beneficial health effects of sleep extension shows that extended sleep can lead to a significant reduction in intake of free sugars. So, sleep duration is a potential novel behavioural target to influence food choice, and contribute to maintaining a healthy weight. Sleep extension is a feasible intervention in healthy adult short-sleepers, but there is a need for randomised controlled trials in overweight/obese study populations to confirm the efficacy of this strategy in conjunction with weight loss advice. But the current guidelines for management of weight and metabolic conditions may benefit from inclusion in sleep hygiene advice.”
Professor James Stubbs, Professor of Appetite and Energy Balance, University of Leeds, told the conference that weight loss leads to physiological and behavioural changes that predispose people to weight regain.
He said: “Weight loss maintenance interventions need to adjust individual energy balance behaviours to navigate around physiological resistance to weight loss. Some of the novel and most promising behavioural intervention components that may help long-term weight loss include the use of tracking technologies, self-regulation and motivation, and emotional regulation and stress management. In the near future, individuals will be able to routinely use digital tracking technologies to help navigate their energy balance behaviours and maintain a healthy weight. Developing an analytical and predictive framework using such technologies is key to developing the next generation of weight loss management interventions based on novel screening, tracking and personalised navigation tools.”
The impact of meal times and circadian disruption (the body’s internal clock) on energy balance and metabolism was explored by Dr Leonie Ruddick-Collins, Research Fellow, Rowett Institute, University of Aberdeen. She said: “The circadian system plays an extensive role in regulating the timing of key metabolic processes, including glucose control, lipid metabolism, energy expenditure and digestive processes. Several of these rhythms peak in the morning, suggesting that eating earlier in the day may be optimal for better digestion, blood glucose control and regulation of energy balance. Light and dark cycles primarily regulate our master clock in the brain but meal timing can act as a ‘timer’ or external cue, which can also regulate our circadian clock, causing misalignment and increasing the risk of developing metabolic diseases.”
Other speakers included Dr Katy Sutcliffe, Associate Professor, University College London, who discussed supportive relationships in the context of successful weight management programmes, and George Thom, Research Associate, University of Glasgow, who questioned if there is an optimal diet for weight management and metabolic health.
Thom said: “Weight loss improves all obesity-related diseases, regardless of the macronutrient composition of the diet. Emerging evidence suggests that total diet replacement led programmes are most successful on average, but people vary in preferences and there is no ‘one-size-fits-all’ approach when it comes to weight management. We aim to get people to make dietary changes for life, but there are few habits that we start, and maintain forever. Most things are done in phases and maybe weight management is a bit like that. Optimising adherence to any calorie controlled diet following weight loss is the most important factor for long term success. Weight loss maintenance remains the biggest challenge and is undermined by an obesogenic environment that is counter-productive to sustaining lifestyle changes, despite our best intentions.”
Ayela Spiro, Nutrition Science Manager at the British Nutrition Foundation, said: “It is clear that different weight loss strategies can work for different people but finding effective strategies for long-term sustainability of weight loss continues to be the major challenge. There is a growing body of evidence that highlights the complexity of factors that may impact on successful weight management and these reflect that it is not just what eat that is important, but also how and when we eat.