Ever wonder why certain individuals seem predisposed to gaining weight and find fat loss harder than others?
Part one: Activity adaptation
As we restrict energy our bodies makes adaptations to try and avoid weight loss. One of the key adaptations we make is a reduction in activity. This tends to be subconscious and is also apparent in animals on energy restricted diets.
In fact, people lose differing amounts of weight despite being in the same relative energy deficit. For example if you put people in a 25% energy deficit (i.e everyone eats 75% of the calories they need to maintain their weight) they wouldn’t lose the same relative amount of weight this can be largely attributed to differences in activity compensation. Some people reduce their activity a lot when energy is restricted and others don’t.
Reduced activity energy expenditure can explain why some people lose more weight than others when dieting. Activity can account for a large amount of the variance in weight loss.
One study showed mice who lost the most weight on a 30% energy deficit diet were the most active. Those who lose the least weight were the least active. Of note is that the differences in weight lost amongst the mice were attributable to differences in activity levels.
One way to try to account for this is by monitoring your activity when dieting. This can be done by using a step count devise e.g. fitbit or app on your phone.