Skipping Breakfast? Not So Fast!

It has been previously established that it is good if breakfast is the largest meal of the day:

Mythbusting Breakfast-Time

…with meals getting progressively smaller thereafter.

But what if we want to do intermittent fasting, and perhaps decide to skip breakfast for it?

Circadian rhythm matters

Regular readers may recall that circadian rhythm is about far more than just our sleep/wake cycle, and the daily ebb and flow of our neurotransmitters/hormones (including hormones related to appetite and digestion) and metabolism have wide-reaching effects on how our body will handle such things as exercise, food, sex, and more.

See also:

• The Circadian Rhythm: Far More Than Most People Know
• The Other Circadian Rhythms

Researchers (Dr. Yannan Zhang et al.) did a cross-sectional study of 15,959 adults aged 35–74 years found that people who skipped breakfast frequently are more likely to have metabolic syndrome (MetS).

First, what is metabolic syndrome? It’s a cluster of conditions that increases the risk of cardiovascular disease and includes abdominal adiposity plus at least two of the following: elevated fasting blood glucose or diabetes, high blood pressure, elevated triglycerides or lipid-lowering treatment, and low HDL (“good”) cholesterol.

The results, in numbers:

• Main findings: participants who skipped breakfast at least four times weekly had 25% higher risk of having MetS than those who never skipped breakfast after adjusting for demographic and lifestyle factors.
• Subgroup findings: the association was stronger in men, who had 33.3% higher risk of MetS, and in participants with a BMI of 24.0–27.9 kg/m², who had 32.8% higher risk.
• Individual risk factors: frequent breakfast skipping was associated with 32.8% higher risk of elevated fasting blood glucose, 24.9% risk of high blood pressure, and 37.7% higher risk of low HDL cholesterol, but it wasn’t significantly associated with abdominal adiposity or elevated triglycerides.

You can find all these numbers in the full paper, which you can read here: Relationship between skipping breakfast and metabolic syndrome among adults aged 35–74 years: a cross-sectional study in Northwest China, 2018–2020

So, those are the consequences, but what’s the mechanism?

The study was associative, so didn’t cover this, but we at 10almonds have covered this previously:

Breakfasting For Health? ← in which we cover the science of intermittent fasting in the context of the circadian rhythm.

Short version is: your body cares what time of day it is, and will do metabolically better or worse depending on what you do at different times of day. Eating the largest meal of the day in the morning is best of all, but failing that, having at least some meal in the morning is better than none. If you want to do intermittent fasting, it is better to have an early dinner (and thus begin your fast early in the evening) than a late breakfast (to end your fast late).

See also: What Size Breakfast Is Best, By Science?

Not only that, but there are also other health-related reasons to enjoy a good breakfast, too:

Meal Timings vs Osteoporosis Fracture Risk

Want to learn more?

Check out:

Fasting, eating earlier in the day or eating fewer meals—what works best for weight loss?

Enjoy!