Is Skipping Breakfast Good for Weight Loss? What the Science Says

For years, we’ve been told that skipping breakfast is a bad idea.

Breakfast is supposed to stoke your metabolism so that you burn more calories throughout the day. Without it, your stress hormones will skyrocket, your muscles will waste away, and you increase your risk for diabetes and heart disease.

Is breakfast really the most important meal of the day? Or will you do just as well without it?

Should I Skip Breakfast?

If I was trying to sell you on the importance of breakfast, here’s how I’d go about it.

First, I would mention the observational studies showing that people skipping breakfast tend to weigh more than those who don’t [2].

In a 2013 study, researchers found that participants who ate breakfast every day gained less weight than those who didn’t [7]. They also reduced their risk of a spectrum of metabolic conditions, including cardiovascular disease and diabetes.

Next, I would tell you about the research that shows tapering down your calorie intake — eating breakfast like a king, lunch like a prince and dinner like a pauper — leads to a faster rate of weight loss.

In one such study, researchers assigned a set of overweight and obese subjects to one of two groups [5]. Both groups ate the same number of calories per day, but with one key difference.

The first group ate progressively smaller meals over the course of the day. Breakfast contained 700 calories, lunch 500 calories and dinner just 200 calories.

The second group did the exact opposite. They ate a small breakfast and a large dinner.

After 12 weeks, the big breakfast group lost, on average, 20 pounds in weight. Subjects eating a small breakfast and large dinner lost just eight pounds.

If Kellogg’s were paying me a vast amount of money to persuade you that breakfast was indeed the most important meal of the day, I’d stop there.

But that would mean ignoring all the research showing that breakfast is nowhere near as important as we’ve been led to believe.

What Happens to Your Body If You Skip Breakfast?

It’s true that people who skip breakfast are, on average, fatter than people who don’t. But this has less to do with breakfast itself than it does with a lifestyle that lends itself to overeating and a lack of physical activity.

“Epidemiology has consistently associated infrequent breakfast consumption with increased risk of adiposity, diabetes, and cardiovascular disease,” write researchers from the University of Bath.

“Yet, these findings do not infer causality because habitual breakfast consumers also tend to be nonsmokers, consume less fat and alcohol but more fiber and micronutrients, and critically, are more physically active. It therefore remains to be established whether daily breakfast is a cause, an effect, or simply a marker of a healthy lifestyle.”

You might, for instance, observe that cars with a Ferrari badge go a lot faster than most other cars without a Ferrari badge.

But that has less to do with the badge than it does with the massive engine sat under the bonnet.

Likewise, most studies that show a link between breakfast and weight loss are “observational” in nature. They might show a connection between eating breakfast and a reduced risk of weight gain. What they don’t show is that one is causing the other.

Is Skipping Breakfast Good for Weight Loss?

A number of controlled trials have tested the proposed link between breakfast and weight loss. All show much the same thing. Skipping breakfast doesn’t have a great deal of impact on your ability to lose weight one way or the other.

Back in 1992, scientists from Vanderbilt University found that people who normally ate breakfast lost more weight when they were told to skip it [6]. And those who normally skipped breakfast lost more weight when they ate breakfast.

Overall, the findings show no effect of eating versus skipping breakfast.

Research published in the American Journal of Clinical Nutrition shows similar results [3]. Subjects eating breakfast lost no more weight than those who didn’t.

“Our simple question was (when it comes to weight loss), does it help to eat breakfast? And the answer seems to be probably not,” says study author David Allison.

As part of the Bath Breakfast Project, researchers from the University of Bath assigned participants to a fasting group and a breakfast group [1].

After six weeks, nothing much happened.

People who ate breakfast were more active throughout the day. But all they were doing was burning off some of the calories they’d eaten for breakfast. The extra physical activity didn’t lead to any weight being lost.

Breakfast had no impact on resting metabolism. Nor did it lead to a meaningful suppression of calorie intake later in the day.

Thyroid hormones that regulate resting metabolic rate were not adversely affected by fasting. Similarly, there was no difference in a range of hormones involved in appetite control.

From study author Enhad Chowdhury:

“The common conception that breakfast may facilitate weight management by ‘kick-starting metabolism’ was not evident at all in our results, with resting metabolic rate stable within just 11 calories per day from the start to the end of the intervention in both groups.”

Breakfast and Appetite

Depriving people of breakfast can mean they end up eating more at lunch [8]. But those additional calories don’t compensate entirely for the calories they missed at breakfast. By the end of the day, the breakfast skippers still ate fewer calories overall.

Other studies fail to show that skipping breakfast leads to an increase in calorie intake at lunch, or increase appetite during the afternoon [11].

Researchers at Brigham Young University took a group of women who don’t normally eat breakfast, and split them into two groups – breakfast eaters and non-breakfast eaters [9].

Breakfast eaters were told to eat at least 15 per cent of their calories for the day before 8.30am. Non-breakfast eaters didn’t eat anything until after 11.30am.

On average, the breakfast eaters ended up consuming an extra 266 calories per day. As a result, they gained 1.5 pounds (0.7 kilograms) during the four-week study.

The people eating breakfast didn’t end up eating less at lunch or dinner. Nor did they increase their physical activity to compensate for the extra calories eaten. Getting non-breakfast eaters to eat breakfast simply led to them eating more and gaining weight.

Interestingly, skipping breakfast and then exercising in a fasted state has been shown to reduce daily calorie intake [12]. And this drop in calorie intake didn’t come solely from breakfast. Subjects also ate less later in the day.

To quote the researchers directly:

“What we did not expect to find was that when participants fasted they also consumed less energy during their evening meals and snacks compared to the days when they ate breakfast. The reduced 24-hour energy intake on fasting days was not only due to the fact that breakfast was skipped but also due to a decreased energy intake at night.”

Summary: Should I Skip Breakfast?

The bottom line is that skipping breakfast does not automatically increase your risk of weight gain. Nor do people who eat breakfast end up losing weight more quickly than those who don’t. It all comes down to individual preferences and what works for you.

If you find that skipping breakfast leaves you hungry, tired and unable to concentrate, then don’t skip breakfast. But if breakfast isn’t your thing, or you don’t get peckish until the afternoon, there’s nothing wrong with starting the day with a cup of coffee and little else. It’s not something that will make or break your diet.