A study on eating more during long periods of inactivity

February 9th, 2017 by

Here’s some interesting results from a study that looked at how eating more during long periods of inactivity can lead to muscle loss.

In this study, researchers split 19 healthy men into two groups. Both groups remained in bed for 5 weeks. The difference between groups was that one group (lets call them Group 1) consumed a diet to match the amount of calories they’d burn throughout the day from basically lying there. The other group (Group 2) consumed enough calories to maintain their weight as if they were still being active (even tho they weren’t). So the second group ate more calories, while the first group ate less.

Before and after the study, the researchers measured the subject’s weight, fat mass and fat-free mass (e.g. muscle). They also did an ultrasound on each subject’s vastus lateralis (one of the muscles in the quads) to measure muscle thickness. What they found was that both groups lost weight with no significant difference between the two. They also found that those in Group 2 (those who ate more) had a greater decrease in muscle thickness for the vastus lateralis.

Now here’s where it gets really interesting: 9 out of 10 subjects in Group 2 gained fat. So this may not be too surprising as they were eating more calories than they required. However, 5 out of 9 people gained fat in Group 1. So it sounds like the researchers overestimated the calorie needs for Group 1. Ok, fair enough. Sometimes things don’t always work out the way you intended. We’ve all been there, right? Regardless tho, what they found was that those who gained fat (from both groups) actually lost more fat-free mass.

So it looks like there could be an association between fat accumulation, inactivity and muscle loss. Just keep in mind that this is just one, small study, and this may be part of a bigger picture, but if you’re planning on taking an extended break from training then you may want to watch how much you eat during this time as it may have an influence on not only fat gain, but also muscle loss.

 

For more information:
Biolo, G et al. Positive energy balance is associated with accelerated muscle atrophy and increased erythrocyte glutathione turnover during 5 wk of bed rest. Am J Clin Nutr. 2008 Oct;88(4):950-8.