Is Eating One Meal a Day Healthy?

Eating one big meal a day saves time, is convenient and can feel like a feast. It's not the healthiest way to divide up your calories, however. When you fast for most of the day and eat at just one time, you're putting yourself at risk for conditions that range from elevated blood sugar levels to long-term obesity.

When you spread your meals throughout the day, your stomach and digestive system don't have to work as hard. If you eat just one meal, however, there is increased pressure on your digestive system to work through all that food. Your heart must work harder to send extra blood to your gut, which can raise your blood pressure levels over time. If you're susceptible to heartburn, a big meal also raises your risk of acid reflux.

In clinical trials, scientists have discovered that eating a single meal a day has negative health effects in the long term. In one study published in 2007 in the journal "Metabolism," subjects who had all of their daily calories in one meal developed higher blood sugar levels and elevated levels of ghrelin, a hormone that controls appetite. The researchers concluded that over time, eating a single meal daily could put people at higher risk of developing serious conditions such as diabetes, stroke and heart disease.

When you skip regular meals, your hunger increases. So even if you have a bigger calorie allowance at your single daily meal, you still may overeat. In some instances, you can gain weight over time by eating one meal per day even if you eat a moderate number of calories. In a trial published in 2012 in the "Journal of Circadian Rhythms," mice that ate just one large meal daily gained more weight during the study period than mice that ate two meals a day, even though the two groups had the same total amount of food.

Not all of the side effects of consolidating meals are physical. Some relate to your mental health and can affect your concentration and academic or job performance. According to Evelyn Tribole, author of "Eating on the Run," people who consistently skip regular meals are slower to make decisions, accomplish less work and have poorer concentration. The human brain runs on glucose, and stores of glucose typically last for just four to six hours after eating a meal. Thus, if you go longer than that without eating in favor of having just one meal daily, it may affect your mental health.