By Sarah Churchill, M.S., Dietetic Intern
Brigham and Women's Hospital
Many Americans struggle with losing weight. They feel frustrated by repeated attempts at weight loss.
Fad diets claim successful weight loss, but none of them are proven to work. It's clear that eating fewer calories is important to lose weight. But there is conflicting evidence on the specifics.
One area of debate is when to consume calories throughout the day. Is eating three times a day best to achieve weight loss? Or is it better to eat more — or less — frequently? These are tough questions. Some diets suggest eating every two to three hours. Others suggest limiting it to three times per day or even only twice a day.
Eating More than Three Times a Day
There does appear to be an inverse association between weight and eating frequency. That is, the heavier a person is, the less often they eat. In fact, research suggests that people of normal weight and formerly obese people who have maintained their weight loss eat about four times per day, compared with obese people. Here are some potential benefits and disadvantages to eating more than three times per day.
- A decrease in hunger and an increase in fullness, which can potentially prevent overeating. In fact, when people become very hungry the risk increases that they will choose unhealthy high-calorie foods, such as pizza and soda. This can lead to eating too much at one sitting.
- More opportunities to consume healthy foods such as fruit, vegetables and whole grains.
Potential disadvantages include:
- Choosing snacks that do not leave us satisfied, which can lead to overeating later in the day.
- More mindless eating. Unhealthy food options are everywhere to tempt us. We learn to respond to cues, such as food availability, rather than hunger and fullness. This can lead to overeating. Eating three meals a day can help us resist tempting foods and overeating. This helps promote weight loss.
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What the Science Says
The limited research suggests that eating three structured meals per day compared with fewer than three meals per day can help control appetite and lead to feelings of fullness.
A 6-month feeding trial of 51 people looked at the effect of eating frequency on hunger, energy intake and weight loss. Participants were split into 2 groups. The "gorging group" ate 3 meals per day. The "grazing group" ate about 100 calories every 2 to 3 hours. Grazers ate about 6 times per day. Participants were given a calorie limit based on their individual weight-loss goals.
By the end of the study, all of the participants had lost weight. However, there was no difference in the amount of weight lost between the two groups. But people in the grazing group experienced significantly less hunger. But this did not lead to more weight loss for the grazing group.
An 8-week study looked at the difference in weight loss between participants who ate 3 times a day versus 6 times per day. They all reduced their food intake by an average of 700 calories a day. Half of the 16 participants ate 3 times per day. The other half ate 6 times per day. Participants in each of the groups lost the same amount of weight. This was a small study. And it did not look at long-term weight loss.
To sum up, eating fewer calories helps you lose weight. But when you eat or how often you eat does not affect weight loss. We need more long-term studies to determine the optimal number of times a day to eat.
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Eating Frequency versus Food Quality
Replacing high-calorie foods with healthier low-calorie ones can help decrease calories without limiting the total volume of food you eat. A 10-month study of 189 patients found they were able to lose weight by reducing calories from drinks and choosing foods with low energy density.
Energy density is the amount of calories per gram of food. Vegetables have a low energy density. Red meat and butter have high energy density. It may be possible to lose weight by replacing high energy density foods with foods that are lower in energy density. For example:
- Replace 1 cup of pasta with ½ cup pasta and 1 cup of broccoli to save 100 calories.
- Substitute 1 cup of white rice with ½ cup rice and 1 cup of spinach to save 125 calories.
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Tips for Successful Weight Loss
It appears eating at least three times per day can keep you full and reduce hunger. This is good for weight loss. Eating fewer than three times a day puts you at risk for overeating and choosing less healthy foods.
Also, the quality of food can help with hunger management and weight loss. By eating foods with low energy density, like fruits and vegetables, you'll feel fuller longer.
So, how do you lose weight? Everyone is different in the food they like, their medical histories and their lifestyles. Meeting with a registered dietitian is one way to meet your goals. He or she can assess your needs and design a nutrition plan just for you. Here are a few additional tips for successful weight loss:
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Sarah Churchill is a dietetic intern at Brigham and Women's Hospital. She graduated with a B.A. in American Studies from Georgetown University and a M.S. in Nutrition and Health Promotion from Simmons College. Sarah also holds an A.A.S in Culinary Arts from Le Cordon Bleu College of Culinary Arts in Boston MA.