No More Late Night Snacking!

Health care professionals, nutritionists, and diet gurus have been telling us for years that late-night eating is an efficient way to pack on the pounds. This theory has been supported by research in the past, and now there’s a new study to reinforce the claim.

On September 4, 2009, The International Journal of Obesity reported that researchers at Northwestern University compared the weight of mice given access to food during the day with those allowed to feed only at night. Mice are nocturnal, so day eating for them is like night eating for humans.

Both groups of mice received an identical high-fat diet and were able to eat as much as they chose. At the close of the six-week study, mice fed by day gained more than double the weight of those fed by night, even though both groups consumed the same number of calories. Day-feeders increased their weight by 48%, while night feeders increased theirs by only 20%.

A previous study with humans provides further support for the theory. An article published in the American Journal of Clinical Nutrition reported that researchers at Kronos Longevity Research Institute in Phoenix found that subjects who ate between 11 p.m. and 5 a.m. on at least one day over a 3-day period gained 13.6 pounds over the next 3.5 years. Subjects who ate during the day gained only 3.7 pounds.

Both groups were allowed to eat as much as they wished. Of the 94 participants, 65 were day eaters and 29 were night eaters. For the humans in this study, night eating was a reliable predictor of weight gain.

Arline D. Salbe, PhD, senior research fellow at the Kronos Institute and an author of the human study speculates that as lifestyles and sleep schedules change, more people are at risk for obesity and likely to become overweight from nighttime eating.

Researchers are uncertain as to why night eating leads to weight gain. Deanna Arble, doctoral student at Northwestern University and lead author of the mice study suggests that because night eating is out of sync with human circadian rhythms, it disrupts the natural flow of energy within the body and somehow leads to an increase in weight.