New research suggests that when you eat may be as important as what and how much you eat, when it comes to losing weight. Scientists call this new weight loss strategy “time-restricted feeding,” and it usually means restricting one’s daily calories to a window of time – usually eight or nine hours.
Several promising new studies suggest that time-restricted eating boosts metabolism and enables the body to more easily lose body fat and keep blood sugar levels stable. One study reported in the International Journal of Obesity found that dieters who ate their main meal before 3:00 p.m. lost more weight (22 pounds) compared to than those who ate most of their calories later (17 pounds). (Both groups followed the same diet and exercise program.) Preliminary studies found that subjects who restrict daily calories to an eight-hour window, lose more weight and body fat; and retain more muscle mass compared to subjects who eat the same calories but enjoy their meals over a longer period of time. What’s more, at least one study suggests that subjects who stuck with limiting their eating hours, were more likely to keep from gaining weight after losing weight.
The bottom line: Your body has some ability to tell time, stemming from our hunter-gatherer ancestors who were active and ate during daylight hours and slept when it was dark. The researchers believe that the body has evolved in a way in which metabolism is revved and more efficient earlier in the day. For example, earlier in the day, your body is more efficient at stabilizing blood sugar levels. After 3:00 pm or so, studies show that eating carbs can lead to rises in blood sugar levels and other negative metabolic effects.
Some popular new diet books, notably the 8-Hour Diet and Budda’s Diet have one core principle—limit daily calories to a specific window of time.
As an example, here is how you could divide your meals into an 8-hour eating window:
Breakfast: 9:30 to 10:00 am
Lunch 12:30 to 1:00 pm
Dinner 5:30 to 6:00 pm
Here are three steps to transition to a Body Clock diet.
- If you eat dinner after 7:00 pm, start by shifting your last meal up by an hour.
- If you currently eat your daily meals over a 12-hour window, shift to an 11-hour window. Once you adapt to that, then transition to a 10-hour window until you get to an 8- or 9-hour eating period. There is no magic to this, the key goal is to try to eat the vast majority of your daily calories (and especially carbohydrate calories) earlier in the day. It also helps avoid mindlessly munching while relaxing after dinner.
- You can follow any type of eating pattern you like, but try to focus on the advice we always give. Eat a primarily plant-based diet (read: lots of veggies, fruit and whole grains) with plenty of filling lean protein at each of your main meals.