Women who wake up and go to bed at the same time each day have lower levels of body fat, according to a study of more than 300 women from Brigham Young University in Utah. Chaotic sleep habits cause your internal clock to go haywire, which in turn causes your body to secrete fat-storing hormones like cortisol. The sweet spot? Try not to stray an hour from your usual sleep pattern, the study authors say. More than a 90-minute difference in sleep and wake times were linked to more body fat. (Tossing and turning? Check out these 100 tips to sleep better every night.)
This may explain why the fat-burning effects of eating more protein were confirmed in a study published in the American Journal of Physiology. One group was fed a high-protein diet (just over 1 gram per pound of body weight per day) while the second group consumed an amount closer to the lower recommendation of the RDA (recommended dietary allowance). The group eating the higher-protein diet burned the most fat.