If you grew up in Western society, you've likely heard (repeatedly) that breakfast is the most important meal of the day. Skipping it is like skipping your morning shower—you just don't do it.
Lately, though, things have changed. You can skip breakfast and feel good about it, publicly and privately.
You aren't skipping breakfast. You're practicing intermittent fasting for its health benefits.
But this semantical switch doesn't mean missing breakfast is your optimal health strategy. It merely suggests fasting works for some folks.
This article will help you decide if meal skipping is a good idea. Let's start by reviewing what happens when you skip breakfast.
Skipping Breakfast = Intermittent Fasting
Intermittent fasting entails forgoing (or reducing) calories for 12–36 hours. If you skip breakfast but no other meals, you're likely in the 12–18 hour range and in the ballpark of 16/8 fasting.
Taking food breaks has pros and cons. You're sacrificing growth for repair—the comfort of eating for the austerity of fasting.
Still, there are few cons to a 12-hour overnight fast. Skipping the nighttime "sneaky snacks" is better for sleep, metabolic health, and weight management.
As you creep up the fasting ladder, the trade-offs loom larger. Like exercise, fasting is a stressor.
Some stress is okay (your usual Tuesday workout), but too much can be harmful (running a marathon while towing a 3,000-pound car—the British super-athlete Ross Edgley actually did this.[*])
Different people have different stress tolerances, of course. Some breakfast skippers thrive on 16 hours of daily fasting. Others feel weak, tired, and foggy.
Your eating patterns should promote health in the long term without sacrificing energy, mood, or cognition in the short term. Let's review the pros and cons of skipping breakfast so you can achieve this goal.
Benefits of Skipping Breakfast
Skipping breakfast may help you burn more fat while feeling sharper.
#1: Weight loss
If you eat within a shorter window, you'll probably eat fewer calories. It's an intelligent weight loss strategy.
A 2019 meta-analysis of several studies found that skipping breakfast was associated with lower calorie consumption and less weight gain.[*] But there's a caveat. "As the quality of the included studies was mostly low," the authors warn, "the findings should be interpreted with caution."
#2: Fat burning during exercise
Fasted exercise helps you burn body fat. In one trial, overweight men burned 45% more fat while fasted than fed.[*] Other research showed large growth hormone bumps (1300% in women and 2000% in men) after a 24-hour fast.[*] Hypothetically, more growth hormone means more fat burning.
Another study suggests that 16/8 fasting reduces fat mass without muscle loss in resistance-trained men.[*] The crucial detail is that breakfast skippers didn't reduce calorie or protein intake.
Some adaptations, however, appear to be gender-specific. For example, women have better skeletal muscle adaptations when they exercise after eating[*]. Also, a 2013 study found no effect of intermittent fasting (combined with interval training) on body composition in overweight women[*].
#3: Cognition
Not everyone feels sharper while fasting—one study found breakfast enhanced memory in older adults[*]—but some do. Why? Possibly because fasting boosts levels of:
- Orexin-A and adrenaline, both linked to alertness[*][*]
- Ketones, molecules that serve as clean, efficient brain fuel[*]
Conversely, high blood glucose levels (can you say banana pancakes?) have been shown to impair cognition.[*]
#4: Time savings
No elaboration needed here. If you skip breakfast, that slot opens for work, play, planning 100-kilometer open-water swims with a log tied to your waist (another of Edgley's hobbies), and other fine uses of your time.
Cons of Skipping Breakfast (Is Skipping Breakfast Bad?)
Let's review the other side of the coin, starting with sleep.
#1: Circadian rhythm disruption
Light and food regulate your 24-hour wake-sleep cycle, the circadian rhythm. Your genome switches on and off with this rhythm, so keeping it tuned is synonymous with staying healthy.
Here's a simple heuristic. Bright light plus protein in the morning wakes you up while fasting overnight promotes restful sleep. One study found that a high-protein breakfast leads to higher night-time levels of melatonin (the sleep hormone) in Japanese students.[*]
In other words, skipping breakfast could impair sleep quality.
#2: Nutrient deficiencies
Eating fewer meals means fewer opportunities to consume vitamins, minerals, protein, and other critical nutrients. Ninth graders who skipped breakfast had more nutrient deficiencies, one study found.[*]
Protein is the crucial nutrient to track. It's easier to consume 1.6 grams of protein per kilogram bodyweight (about 150 grams for a 200-pound person) for optimal muscle maintenance if you start eating earlier.[*]
#3: Lower energy
Some people find fasting improves their energy, focus, and mood. Others find the opposite.
You don't need data from the lab to see where you fall. Just skip breakfast once or twice and see how you feel.
Keep in mind, however, that adapting to a fasting (or Keto) lifestyle can take a few weeks. When you're used to eating carbs, you don't become a fat-burning machine overnight.
A gentle way to "fat-adapt" is to practice 12-hour overnight fasting while transitioning to a high-protein Ketogenic diet. Adapt to Keto first, then skip the morning meal.
Should You Skip Breakfast?
Self-experimentation will provide your answer, but it's worth looking at some general cases.
You might skip breakfast if:
- You have excess body fat to lose
- You have metabolic issues like type 2 diabetes
- You want to burn more fat during your morning cardio
- You feel smarter while fasting
- You do your best work in the morning on an empty stomach
And you should lean towards eating breakfast if:
- You're pregnant, nursing, or trying to conceive
- You're underweight
- Your sleep is suffering
- You aren't consuming adequate protein
- You want to maximize athletic performance[*]
- You're training for something (Edgley eats up to 15,000 calories per day)
- You feel tired, foggy, or grumpy when you skip breakfast
Lots of factors to track, aren't there? Carb Manager can help.
Find your optimal fast with our suite of intermittent fasting features, keep nourished and muscled with advanced food logging, and stay motivated throughout. With a few moments of daily effort, you set yourself up for success—wherever you fall on the breakfast spectrum.
