Scientist Explains Why Fat Loss Is So Hard and Proposes a Novel Solution
Losing weight is notoriously challenging, and maintaining that loss often proves even more difficult. Now, a prominent scientist offers a compelling theory to explain this struggle, pointing to a phenomenon known as 'energy compensation' as a key factor. Professor Lewis Halsey, an expert in environmental physiology at the University of Roehampton, discusses this concept and proposes a potential method to overcome it.
The Plateau Problem in Weight Loss
Many individuals embark on weight loss journeys with the simple formula of creating a calorie deficit by eating less and moving more. While this aligns with thermodynamic principles, real-world results frequently fall short. Professor Halsey highlights that initial progress from increased exercise often stalls after losing only two or three kilograms. This plateau occurs because the body adapts to higher calorie expenditure by conserving energy elsewhere, a process termed energy compensation.
For instance, when someone starts a new exercise routine, their fitness tracker might indicate they have burned 300 calories. However, the body may compensate by increasing hunger, reducing non-exercise activity like fidgeting, or even dampening other physiological functions such as immune response. As Professor Halsey explains, "Metabolic rate while standing is about twice what it is when lying down. If you spend hours lying down rather than standing up, it does have quite an effect." This evolutionary hangover from times when energy was scarce means the body strives to preserve calories, complicating weight loss efforts.
Evidence for Energy Compensation
Research supports this theory, notably a 2015 study by evolutionary anthropologist Professor Herman Pontzer on Hadza hunter-gatherers in Tanzania. Despite their highly active lifestyles, the Hadza people exhibited similar total energy expenditures to sedentary populations in industrialised societies. This finding suggests that the body adapts to regular physical activity by reducing energy allocation to other processes, thereby limiting net calorie burn.
Professor Halsey elaborates, "If you translate that to someone starting to do their walk around the park each night, to start with, the body probably doesn't compensate. But over months, the body will clock what's going on and start to compensate." This mechanism, while logical from an evolutionary perspective, undermines traditional weight loss strategies that rely solely on exercise.
A Strategy to Counteract Energy Compensation
To mitigate energy compensation, Professor Halsey proposes varying exercise routines. He suggests alternating between different types of activities every couple of weeks to prevent the body from adapting. For example, one could switch between high-calorie-burn aerobic exercises like running or cycling and lower-calorie-burn strength training. This approach may keep the body from settling into a compensatory pattern.
"In theory, if you upregulated your activity for a week or two, backed off for a week or two, then repeated this sequence, the body might never learn what is going on and never start to compensate," says Professor Halsey. While more research is needed, this method aligns with broader health advice promoting exercise variety for longevity and effectiveness.
The Broader Role of Exercise in Health
Despite energy compensation challenges, exercise remains crucial for overall well-being. It aids in weight maintenance, improves longevity, combats chronic diseases, and enhances physical function. Professor Halsey emphasises, "The literature also suggests exercise can help with not putting weight back on. So whether energy compensation is a thing or not, it should not put people off doing exercise."
Experts agree that successful weight loss involves multifaceted strategies, including dietary changes, increased fibre intake, better sleep, and varied exercise routines. By understanding and addressing energy compensation, individuals can develop more effective and sustainable approaches to fat loss.
