Weight loss can be tied to when, not just what, you eat

If you are trying to lose weight and otherwise improve your health, you may already be mindful about what you eat during the day. You might skip breakfast. At lunch, you may opt for a salad with lots of veggies, no croutons and low-fat dressing -- on the side, of course.  Then, three o'clock hits.  You're incredibly hungry and craving candy, sweets or chips. You finally cave, eating a candy bar or other treat.  By 6 p.m., you're tearing the kitchen apart, snacking on anything you see.
Despite your best efforts at cutting carbs at meals, you give in to a large helping of pasta or pizza. And then another. But you're still not satisfied. Dessert is calling, and you want something sweet, again. A scoop or two of ice cream satisfies you for the moment, but you continue to graze into the night until finally, you're so tired, you crash into bed.
So what is the cause of all of this diet drama that keeps occurring, almost according to schedule?
The research on front-loading food
It's true that over-consuming calories at any time of day will result in weight gain. But skipping meals or eating too few calories earlier in the day appears to stack the odds against us. The result: Weight loss is hard to come by. In fact, more and more research points to the fact that when you front-load your calories instead, you have a much better chance of shedding pounds.
"What we have seen is that people on diets with the same number of calories who front-load calories to the earlier part of the day fare better in terms of subjective and objective measures of satiety," Freuman said. "They feel more satiated in evening, and there are actually differences in their hunger and satiety hormones ... and this seems to contribute to weight loss success."
One study involving 420 overweight and obese participants divided individuals into two groups: early eaters and late eaters, based on the timing of their lunch (i.e. before or after 3 p.m.). The late lunch eaters also ate lower-calorie breakfasts or skipped breakfast more often than early eaters.
At the end of the 20-week study period, the late eaters lost less weight compared with the earlier eaters (17 vs. 22 pounds on average, respectively) and lost their weight more slowly, despite the fact that both groups ate approximately 1,400 calories per day and consumed similar amounts of fat, protein and carbohydrates.
Another study followed two groups of overweight women with metabolic syndrome on identical 1,400-calorie weight loss diets for 12 weeks. The only difference between the groups was that their calories were distributed differently throughout the day: Both groups consumed 500 calories at lunch, but one group consumed 700 calories for breakfast and a 200-calorie dinner (the "big breakfast" group), while the other group ate 200 calories at breakfast and 700 calories at dinner (the "big dinner" group).
The nutrient content of the meals was exactly the same for both groups, the only difference being that the breakfast and dinner meals were swapped. After 12 weeks, the big breakfast group lost about 2½ times more weight than big dinner group (8.7 pounds for big breakfast group vs. 3.6 pounds for big dinner group) and lost over 4 more inches around their waist.
The big breakfast group experienced a 33% drop in triglyceride levels -- a marker associated with heart disease risk -- while the group that ate the higher-calorie dinner experienced a 14.6% increase. The bigger breakfast group also experienced greater reductions in fasting glucose, insulin and insulin resistance scores, all of which indicate decreased risk for type 2 diabetes, according to the study's authors.
So front-loading calories and carbohydrates is not only favorable in terms of weight loss, it had beneficial effects on other indicators of overall health, including decreased risk for type 2 diabetes and cardiovascular disease.
That second study "opened my eyes," Freuman said. "It wasn't just that people were less hungry and eating less at night, but it pointed to the fact that there might be some sort of underlying metabolic magic going on, where the timing of calories and carbs mattered more than the total amount of calories and carbs eaten in a day. It helped me understand what I was intuitively seeing in my patients."
More and more research is suggesting that when you eat may be just as important as what you eat. And it is very closely tied to the complex science of circadian rhythms.
According to the National Institute of General Medical Sciences, circadian rhythms are physical, mental and behavioral changes that follow a roughly 24-hour cycle, responding primarily to light and darkness in an organism's environment.
Circadian rhythms are driven by biological clocks inside our bodies. The brain has a master biological clock, influenced mainly by light, which tells "peripheral" clocks in the muscles and organs what time of day it is. Because of these clocks, many of the metabolic processes that take place inside us operate at different rates over the course of a 24-hour period.