|Will working out make you cheat on your diet, 'cause it leaves you drained and ravenous? Or is it even a stand-alone weight loss tool with satieting and anti-depressive effects?|
The exercise sessions, which were spaced 1-week apart and to which the subjects were randomly assigned in a counter-balanced fashion lasted 1 hour and were - and this may be an important fact - performed after a standard breakfast.
After the subjects had been sweating in the gy, an ad libitum test lunch was served (that's 3h after breakfast) and fasting/postprandial plasma samples of insulin, acylated ghrelin (AG), polypeptide YY3-36 (PYY3-36) and glucagon-like peptide 1 (GLP-1) and subjective feelings of appetite were measured every 30 minutes for 3h. Nutrient and taste preferences were measured at the beginning and end of each condition using the Leeds Food Preference Questionnaire. In contrast to the "increased appetite" hypothesis, but much in line with what any sane individual would expect, the "[i]nsulin levels were significantly reduced while the GLP-1 levels increased during all exercise bouts".
And what about the lean guys? Does exercise make lean guys hungrier?
In general the results reseachers from the Loughborough University are about to present in a soon-to-be-published paper in the scientific journal "Appetite" clearly support the results Martins et al. observed in significantly heavier subjects.
|Figure 2: PYY3-36 satiety hormone levels (pg/ml) after doing nothing (diet or control) or exercise (=pre-prandial) before, during and after ad libitum test meals (Deighton. 2014)|
- Martins, Catia, et al. "Effect of Moderate-and High-Intensity Acute Exercise on Appetite in Obese Individuals." Medicine and science in sports and exercise (2014).