How Many Meals Should You Eat per Day?

One of the most popular beliefs surrounding meal frequency is that eating more frequently can boost metabolism and aid with weight loss. The theory behind this relies on the thermic effect of food. After eating, there is a small increase in metabolic rate. Despite this, the idea that a person might lose weight through eating more frequently is due to misunderstanding the scale of overall energy exchange within the body.

Processing food for use and storage takes a small amount of energy. This is the thermic effect of food, and it is one of the core components of metabolism alongside exercise and resting metabolic rate. Historically, experts have estimated that the thermic effect accounts for around 10% of a person's caloric intake. The actual amount depends on the foods a person consumes. Studies show that eating foods like protein and carbohydrates results in a greater increase than eating fats because fats are far easier to digest.

The idea that eating more frequently leads to weight loss is one of the longest-lasting nutritional myths. In reality, a person's metabolic rate is largely genetic and only slightly changes due to certain activities. Like most metabolic changes, any change due to meal frequency is temporary and quite minor. Even high-intensity training can only increase the thermic effect of food by about seven to eight calories per hour. Meal frequency has such a small effect that it is measurably negligible. Ultimately, what matters most in weight loss and energy exchange is the amount of food a person eats. Eating two meals of 1000 calories will be functionally identical to eating four meals of 500 calories.

Another common argument behind eating more frequently is that eating often will help balance blood sugar levels. According to the theory, eating big meals will lead to rapid shifts in blood sugar, while eating smaller meals throughout the day will keep everything relatively stable. Because of this, people with diabetes will often shift to a more frequent meal schedule and consume smaller portions at each meal.

Keeping blood sugar below unreasonable levels is particularly important for people with diabetes. If a person could manage their blood sugar just through eating frequency, it could help them avoid major medical issues. There is some scientific evidence that shows that eating two large meals each day leads to greater fluctuations in glucose and insulin responses. However, newer studies have proven that while these findings were accurate, eating large meals less frequently actually leads to better long-term blood sugar levels and body weight due to a variety of small, but compounding, effects.

As is typically the case with nutrition and medicine, there is no magic answer for how often a person should eat to help with blood sugar levels. The current science suggests that eating two large meals a day with high amounts of protein will lead to better blood sugar levels, more satiety, and less hunger. Particularly, eating a large breakfast and a smaller dinner appears to have a significant ability to limit hyperglycemia in people with type 2 diabetes.

Beyond its effects on diabetes, many people consider breakfast to be "the most important meal of the day." This idea exists across many cultures and age groups. After all, a person needs a significant amount of energy to make it through a busy work or school day. Some groups even claim that eating breakfast boosts metabolism and lowers weight. However, the idea that breakfast is more important does not originate from nutritionists or experts but from a 19th-century advertising campaign. In truth, the science behind the importance of breakfast is less clear than people might expect.

Observational studies do show that breakfast skippers are far more likely to be obese than people who eat breakfast. However, it is important to remember that correlation does not equal causation. This link could exist for many different reasons. For example, breakfast skippers might be less likely to care about their overall health and nutrition than breakfast eaters. Alternatively, breakfast skippers might lead busier lives that leave less time for breakfast and healthy meal choices. And, most importantly, there is no strong evidence that eating breakfast boosts metabolism or has any similar effects.

While breakfast might not directly impact weight, eating breakfast might still benefit other health aspects. Notably, the body's blood sugar control might be better shortly after waking up, meaning that eating a large breakfast leads to lower average blood sugar levels than eating later in the day. Without further research, the general expert consensus remains that it is okay to skip breakfast in the morning, but the meal might be beneficial for those with diabetes.

One of the biggest meal schedule trends in recent history is the rise of intermittent fasting. According to proponents of this method, giving the body 12 hours a day without food allows the digestive system to rest. Some people achieve this by having an earlier dinner and then fasting for the full 12 hours. Experts do note that this could lead to worse blood sugar levels, so eating two meals with a shorter fasting period is more optimal.

Intermittent fasting likely has many positive effects. Studies with human and animal subjects show that a period of fasting can improve overall insulin sensitivity, lower blood sugar levels and resistance to neuronal injury and death. Short-term fasting also triggers a cellular process called autophagy. During this clean-up function, the body's cells remove waste products that slowly accumulate and contribute to disease and aging.

Integrating intermittent fasting into a daily schedule can be difficult, especially if an individual is already used to eating throughout the day. It may be easier to slowly reduce the number of meals each day over several weeks. While 12 hours could be the "optimal" period for fasting, the science is still undecided, and skipping even one meal a day could have beneficial effects. When adjusting to a new meal schedule, try to avoid temptations like snack foods that are easy to grab and end a fast. Humans are more likely to eat when they see food, so keep groceries in pantries and refrigerators to help limit this urge.

Though it might be convenient to have a solid answer, there is no single "best" meal schedule for every person. For example, skipping breakfast is fine for most people but eating breakfast could be better for anyone with diabetes. Intermittent fasting might help with weight loss and blood sugar issues, but eating only one meal a day might be difficult for many people. Nutritionists recommend following a meal schedule that is simple to adhere to and meets a person's nutritional needs. A weightlifter has larger caloric and nutritional needs than someone who is more sedentary, so they might need to eat more often to hit their specific goals. Finding a schedule that works for unique lifestyles, health conditions, and nutritional needs is the key.