You may be wondering what is adaptive thermogenesis and why should you care about it? Well if you have tried to lose weight and found that you do well initially, but then the weight loss seems to stop seemingly no matter what you do, adaptive thermogenesis may be partly responsible.
In a previous post I wrote about a position paper released by the International Society of Sports Nutrition. In this paper they described nine positions they were taking based on current research in the area of body composition and diet. One of these positions was in relation to adaptive thermogenesis. In this post I wanted to expand on that point.
When we diet and lose weight our bodies will naturally adjust our metabolism to match our current weight. This is part of a natural process the body uses to help regulate your body weight and energy. However studies have noted that during dieting the extent of the decrease in metabolism is more than what is happening in your body. In short, your body is slowing down its metabolism beyond what would be expected, creating an environment that can stall weight loss and cause quick weight gain once a person ceases their diet.
So what do you do? Well for a long time the thinking was diet combined with exercise would combat this effect and keep your metabolism high. There is some merit to this as studies (such as this one) have shown that in comparison dieters that exercise do experience less of a metabolic slow down than people who diet but do not exercise. However, there is still the slow down. What they have found in other studies is that intermittent dieting leads to both greater weight and fat loss and may reduce compensatory metabolic responses, improving weight loss efficiency.
It is important to note intermittent dieting is not the same as intermittent fasting (a popular diet strategy). In a future post we will go into detail on intermittent fasting but it is too big of a conversation to put into this post. But essentially intermittent fasting involves periods of eating and periods of not eating, for example not eating from 2pm-10am the next day and allowing yourself to eat from 10am-2pm. Whereas Intermittent dieting involves following a diet for two weeks followed by a week of eating “normally” and not restricting calories below your maintenance level. This is a big difference because as this literature review found:
“Intermittent fasting appears to produce similar effects to continuous energy restriction to reduce body weight, fat mass, fat-free mass and improve glucose homeostasis, and may reduce appetite, it does not appear to attenuate other adaptive responses to energy restriction or improve weight loss efficiency”
The longer you continuously diet the less effective your diet will be. This study showed that over a twelve week period weight loss was 33% lower than expected. While as demonstrated by this study, interrupting the energy restricted diet with periods of eating at an energy balance led to greater weight and fat loss than continuous dieting.
So if you have been dieting continuously and have seen your weight loss stall or significantly slow down it may be time to change your strategy. As shown above try reducing your calories for 2 weeks followed by eating at an energy balance for 2 weeks. Combining exercise with this dieting strategy may help you achieve greater weight loss in the long run while reducing compensatory metabolic responses!