Is breakfast really the most important meal of the day?

Breakfast literally means “to break the fast.” It is the first meal of the day after a stretch of not eating overnight. 

Breakfast earned its title as the most important meal of the day back in the 1960s after American nutritionist Adelle Davis suggested that to keep fit and avoid obesity, one should “eat breakfast like a king, lunch like a prince, and dinner like a pauper.”

Though around 15% of people in the United States regularly skip breakfast, many still believe it to be the most important meal of the day. Breakfast provides the body with important nutrients, to start the day feeling energized and nourished. Many also believe that it can promote weight loss.

But is breakfast really the most important meal of the day?

As with most things in nutrition, the answer is complex. While some research suggests that skipping breakfast is not harmful, other research suggests otherwise.

Eating regular meals and snacks, including breakfast, allows for more opportunities throughout the day to give the body the energy and nutrients it needs to function optimally. 

However, as long as a person can fit their nutrients in during other meals, breakfast may not be the most critical meal of the day.

Here is what the science says.

Evidence in support of eating breakfast

Most of the claimed benefits of eating breakfast are primarily derived from observational studies, which cannot prove cause and effect. 

For example, one 2021 systematic review of 14 observational studies found that those who eat breakfast seven times per week have a reduced risk for:

• heart disease
• diabetes
• obesity
• high blood pressure
• stroke
• abdominal obesity
• cardiovascular-related death
• elevated low-density lipoprotein (LDL) cholesterol.

Again, this particular group of studies can only suggest that those who eat breakfast are more likely to have a reduced risk for the cardiovascular and metabolic diseases mentioned above. It cannot prove that breakfast is what is causing it.

However, an analysis of data on over 30,000 North Americans shows that people who skip breakfast may miss out on important nutrients. 

The most common nutrients those who skipped breakfast fell short on include:

• folate
• calcium
• iron
• vitamin A
• vitamins B1, B2, B3
• vitamin C 
• vitamin D.

What is more, one randomized control trial published in 2017 that included 18 participants with type 2 diabetes, and 18 healthy participants found that skipping breakfast caused disrupted circadian rhythms in both groups.

Those who skipped breakfast also experienced larger spikes in blood glucose levels after eating. The authors of the study thus suggested that eating breakfast is vital for keeping our internal clock running on time.