Most Americans are overweight or obese; the situation has become a national health concern. Obesity negatively impacts job performance and is responsible for the expenditure of most of the nation’s health-care dollars. Obesity-related diseases are also the leading cause of death. In response to this problem, Americans have resorted to numerous ineffective fad diets (paleo, Zone, grapefruit, The Cleanse, Atkins, keto, etc.) that have not effectively reduced obesity. Exercising is generally an ineffective way to lose weight; muscles did not evolve to effectively lose weight. (To read more about exercise and the body, click here.)

The only effective way to lose weight is by daily caloric restriction. Caloric restriction also provides several metabolic benefits and leads to longer, healthier lives. The problem with popular diets, exercising, and caloric restriction is that they are difficult to maintain over a lifetime. People feel the urge to eat the foods they are restricting—meat or carbohydrates or fats, depending on the diet—and just generally feel hungry all the time and usually end up binge eating too many calories.

There might be a solution to this problem.

Recent studies have clearly demonstrated that the time of day when we consume our calories is a critical factor. The human body is not a blast furnace, burning up anything we toss in, no matter the time of day. Biorhythms play an important role in how the body handles food. The question then becomes: When is the best time to eat? The studies discussed below suggest that consuming the majority of each day’s calories during the early phase of the day may be most beneficial for weight loss and better health.

Intermittent Fasting and Time-Restricted Eating

Intermittent fasting is a dietary strategy involving recurring periods of fasting. (Liquids are allowed.) The two most common forms are represented by alternate-day fasting (continuously alternating fast and feast days) and a modified version that requires fasting only two days each week. Intermittent fasting can reduce fat mass, plasma glucose, and insulin levels, as well as improve the body’s inflammatory and oxidative status. An alternative method is time-restricted eating. People are instructed to impose an eating window during the day. In studies, time-restricted eating was usually, but not always, associated with the consumption of fewer calories each day. Some studies reported that their subjects lost weight without consuming fewer calories. Time-restricted eating has many benefits: It decreases systolic blood pressure, reduces blood glucose levels, improves the lipid profile, decreases blood pressure and fat mass, and increases insulin sensitivity and glucose oxidation.

In a randomized group of healthy men (mean age: 55 ± 3 years), eating during the early part of the day, as opposed to eating only later in the day, reduced ghrelin levels and decreased fasting glucagon-like peptide 1 (the same thing that current expensive weight loss injections do). In another recent study, eating early led to decreased body weight, fasting glucose, insulin levels, and reduced trunk-to-leg fat ratio. Eating only during the early part of the day also reduced total cholesterol, HDL-cholesterol, and adiponectin levels (a marker of fat-induced inflammation). Another randomized controlled study in 82 young adult females found that eating during the first half of the day reduced fasting glucose, improved insulin resistance, and reduced body weight and fat mass. In addition, eating early in the day reduced blood inflammation and improved gut microbial diversity in these women.

In yet another clinical trial, overweight and obese women were divided into a breakfast group (700 kcal breakfast, 500 kcal lunch, 200 kcal dinner) or a dinner group (200 kcal breakfast, 500 kcal lunch, 700 kcal dinner) for 12 weeks. The breakfast group showed greater weight loss and waist circumference reduction. Fasting glucose and insulin decreased significantly in the breakfast group. Average triglyceride levels decreased by 33.6 percent in the breakfast group and increased significantly in the dinner group. The women also reported feeling less hungry during the day.

Finally, a meta-analysis of 13 clinical trials involving 859 patients showed that early time-restricted eating is an effective strategy to decrease body weight, fat mass, abdominal obesity, and inflammation, but less likely to decrease fat-free mass.

Therefore, it truly does matter when you eat. (To learn more about how food affects the brain, click here.) The take-home message is to eat a big breakfast, eat a small dinner, and never have late-night snacks. Skipping breakfast and then overeating in the evening—a typical American diet—plays a significant role in weight gain and obesity. Furthermore, people who skip breakfast report not feeling satisfied by their food and being hungrier between meals. If this sounds like you, then it may be time to change your mealtimes. This is your new mantra: Eat breakfast like a king, lunch like a prince, and dinner like a pauper.