Consuming fewer calories and eating healthier foods may, alone, not be the smartest way to lose pounds after all. Researchers are increasingly finding that when you eat food is as important for maintaining a healthy body weight as the nutritional quality of the food itself. Rather than eating all day long, it might be healthier to restrict our meals in only a few hours a day, and after exercising.
A study published in the Journal of Physiology in 2010 found that training early in the morning before eating breakfast was a key component to slowing weight gain in men on a high-calorie diet (30 percent above normal intake). Over a six-week period, researchers studied weight gain in three different groups: one group that ate breakfast and did not exercise, one group ate breakfast before morning exercise, and another ate after exercise. Of the three groups, those that ate breakfast after exercising gained the least amount of weight.
Why? The researchers suggested that the key was how meal timing impacts insulin, a hormone responsible for converting energy (food) into either muscle or fat. The fasting training group regulated insulin in a way that turned their hard-earned exercise into muscle, while the the other two groups showed signs of pre-diabetic fatty muscle marbling. In other words, exercise changes how our bodies process foods. Training while hungry helped turn food into muscle, rather than fat.
Now, a new study in the most recent issue of Science has re-kindled interest in just how important meal timing could be on a person’s longevity. Seeking to understand if there were genetic factors involved in changing meal timing, researchers looked at groups of fruit flies that were restricted to eating fewer hours a day, rather than eating all day long.
Exercise changes how our bodies process foods. Training while hungry helped turn food into muscle, rather than fat.
As expected, the flies on time-restricted diets had healthier bodies (for a fly). The researchers suspected that timing affects a specific suite of genes (TCP-1). So, a mutant strain of flies without the same functioning genes were put on the same diet, and, indeed, there were no benefits to meal restriction.
These findings could help researchers determine the precise effects of meal timing on humans down the road.
While the two studies mentioned have shown many positive results from eating more calories during the day, there may be benefits to saving some foods for nighttime. For example, one experimental trial of police officers found that those who ate most of their carbohydrates at night (dinner time) lost more weight than those who ate carbs throughout the day.
For some people it seems, it may be healthier to give in to those late-night cravings.
Indeed, intermittent fasting—eating only a few hours a day—is the dietary secret of some famous actors. Action star and comic-book hero icon Hugh Jackman swears by a super-high calorie diet and exercise routine of intermittent fasting (Jackman eats a whopping 6,000 calories a day to get in shape). I once experimented with Jackman's "Wolverine Diet" for a few weeks and found that fasted exercise and carb-binging at night actually helped me lose body fat, even though I was eating (a lot) more total calories.
In other words, if I restricted the number of hours I ate and consumed most of my calories after I exercised, I could eat many (many) more calories and not gain weight. When I ate was just as important as what I was eating. And, for those looking to lose weight, or not re-gain weight after a successful diet, it's helpful to be more strategic about when we consume our calories.