Do You Really Need Breakfast to Manage Your Weight?

“Breakfast is the most important meal of the day” is one of the most repeated sentences in nutrition. When researchers tested it directly in randomized trials, the result was less clear-cut. This guide looks at how the idea holds up. It is general education, not medical advice.

Where the idea comes from

Many observational studies have found that people who eat breakfast tend to weigh less than people who skip it. But people who eat breakfast also tend to differ in other ways, such as sleep, work schedules, exercise and the rest of their diets. Observational studies cannot say which of those differences matters. That is why researchers ran trials in which people were randomly told to eat breakfast or skip it.

Putting breakfast to the test

• The big review: in 2019 Sievert and colleagues pooled 13 randomized trials in adults in high-income countries. Seven measured weight and ten measured calorie intake. On average, the people assigned to eat breakfast weighed about 0.44 kg more than those assigned to skip it (95% confidence interval 0.07 to 0.82 kg), and ate about 260 more calories a day (interval about 79 to 441).
• A single large trial: in 2014 Dhurandhar and colleagues randomly assigned 309 adults with overweight or obesity to eat breakfast, skip it, or follow healthy-eating information that did not mention breakfast. After 16 weeks, the assignment had no significant effect on weight loss, whether people usually ate breakfast or not.

Reading between the lines

The reviews do not show that skipping breakfast is a weight-loss method. The difference was small, and the authors say the trials were mostly short and of low quality, with all 13 at high or unclear risk of bias. What the results do suggest is that breakfast is not a magic switch that protects against weight gain. Eating breakfast tends to add calories, and for some people it replaces calories they would have eaten later, while for others it does not.

Who this does not apply to

• Children and teenagers. The trials studied adults.
• People with diabetes or on certain medications. Meal timing can matter for blood sugar. Follow your clinician’s advice.
• Anyone who feels unwell without it. If skipping breakfast leaves you shaky, irritable or overeating later, it is not working for you.

Choosing what works for you

• Eat when you are hungry. Both patterns can work. Choose the one you can keep up and that suits your day.
• Look at what is in the meal. A breakfast with protein and fiber may keep you satisfied longer than a sweet pastry. See our guides to protein and fiber.
• Do not copy an extreme. Skipping breakfast is a form of fasting for some people; see our guide to intermittent fasting for how fasting fared in the trials.
• Keep your appetite in the picture. If your appetite is small, our guide to building a balanced plate may help.

If food or eating ever feels stressful or out of control, a licensed professional can help. In the U.S. you can call or text 988 at any time.

In short

The old rule that you must eat breakfast to manage your weight is not backed up by the randomized trials. The evidence is limited, but it says that breakfast is a personal choice, not a requirement.

Sources

• Sievert K, Hussain SM, Page MJ, et al. Effect of breakfast on weight and energy intake: systematic review and meta-analysis of randomised controlled trials. BMJ, 2019;364:l42.
• Dhurandhar NV, Petersen D, Tang X, et al. The effectiveness of breakfast recommendations on weight loss: a randomized controlled trial. American Journal of Clinical Nutrition, 2014;100(2):507-513.