Diets require a lot of consistency: weeks or even months of following a meal plan, daily workout schedule, and specific lifestyle changes such as no alcohol, more sleep. It’s that day-in/day-out effort that ultimately delivers the weight loss and fitness results you want.
Or is it? According to a new study published in the International Journal of Obesity, your body’s resting energy expenditure should change with weight loss, but that during dieting the extent of that decrease is greater than would be normally attributed to what is happening to your body. This process is called adaptive thermogenesis and leads to markedly reduced efficiency of weight So, the trick with diets is to attenuate adaptive thermogenesis.
It may be a good idea to lay off the diet every now and again if you want to see real results.
A team of researchers funded by the National Health and Medical Research Council (NHMRC) of Australia gathered two groups of participants to undergo a reduced-calorie diet. For sixteen weeks, the participants reduced calorie intake by 33%. However, one of the groups only followed the diet for two weeks before taking a two-week break, repeating this cycle for thirty weeks so they still ended up with sixteen weeks of dieting.
After the diet, the researchers examined the results and found that the intermittent dieting group lost more weight during their diet period. Not only that, but they were better able to maintain the weight loss after the diet finished. They lost eight kilograms more than the control group during the six months after the study period.
The lead researcher explained why this happens, “When we reduce our energy (food) intake during dieting, resting metabolism decreases to a greater extent than expected; a phenomenon termed ‘adaptive thermogenesis’ — making weight loss harder to achieve. This ‘famine reaction’, a survival mechanism which helped humans to survive as a species when food supply was inconsistent in millennia past, is now contributing to our growing waistlines when the food supply is readily available.”
On the flip side, diets that only last one to seven days did not prove as effective for promoting and maintaining weight loss. It was only after the diet was sustained for two weeks at a time that the body adapted effectively. Intermittent days of fasting and feasting “were not any more effective than continuous dieting.”
Want to kick your weight loss efforts up a notch? Try intermittent dieting—two weeks of dieting followed by one to two weeks of normal eating. Not only will this make it easier for you to adapt to the new eating habits, but it can encourage better long-term results as well.
1. N M Byrne, A Sainsbury, N A King, A P Hills, R E Wood. “Intermittent energy restriction improves weight loss efficiency in obese men—The MATADOR study.” International Journal of Obesity, 2017; DOI: 10.1038/ijo.2017.206.