You ate breakfast. A bowl of cereal, maybe a muffin with your coffee, or a cup of flavored yogurt. Yet by mid-morning your stomach is growling, your energy has dipped and the office donuts are calling your name. The problem probably isn’t that you ate breakfast, or that you didn’t eat enough. It’s what was on your plate.
Key Takeaways
- The most common breakfast mistake is eating a meal that’s mostly sugar and refined carbs with little protein, such as sweetened cereal, pastries, white toast with jam, or sugary yogurt.
- These breakfasts can cause a blood sugar rise followed by a dip a few hours later. In a study of more than 1,000 people, bigger dips after meals were linked to feeling hungrier sooner and eating more over the rest of the day.
- Protein keeps you full longer, steadies blood sugar, and takes more energy for your body to digest than carbs or fat.
- Skipping breakfast doesn’t slow your metabolism, a randomized trial found. But for many people, a well-built breakfast makes the morning easier.
- The fix is simple: build breakfast around protein and fiber, and keep added sugar low.
The answer: too much sugar, not enough protein
Many classic breakfast foods are, nutritionally speaking, closer to dessert. Sweetened cereals, granola, pastries, muffins, flavored oatmeal packets, fruit juice and many flavored yogurts are high in sugar or refined starch and low in protein and fiber.
These foods are digested quickly, so blood sugar rises fast. Your body responds by releasing insulin to bring it back down, and in some people blood sugar then drops below where it started. That dip often arrives two to three hours later, right around 10 a.m. for many people. It’s when hunger, cravings and that sluggish, foggy feeling can set in.
What the research shows
Blood sugar dips predict hunger. In a 2021 study published in Nature Metabolism, researchers at King’s College London and their colleagues gave 1,070 people in the UK and US standardized breakfasts and tracked their blood sugar with continuous glucose monitors. People whose blood sugar dipped further two to three hours after eating felt hungrier, ate their next meal sooner and ate more calories over the following 24 hours. The size of the dip mattered more than how high blood sugar spiked.
Protein at breakfast curbs cravings. In a small study of overweight young women in their late teens who usually skipped breakfast, a breakfast with about 35 grams of protein led to greater fullness and less evening snacking on high-fat, high-sugar foods than a lower-protein breakfast. Protein triggers the release of gut hormones that signal fullness and slows how quickly food leaves the stomach.
Protein also takes more energy to digest. Your body uses energy just to break down food, a process called the thermic effect of food. Roughly 20% to 30% of the calories in protein are used up digesting it, compared with about 5% to 10% for carbohydrates and very little for fat. This isn’t a dramatic “metabolism boost,” but over time it makes protein the most filling and least easily stored part of a meal.
Wait, isn’t skipping breakfast the real mistake?
Not necessarily. The idea that breakfast “kick-starts your metabolism” doesn’t hold up well. In the Bath Breakfast Project, a randomized trial from the University of Bath in the UK, lean adults who ate a large breakfast every day for six weeks had no difference in resting metabolic rate compared with those who skipped it. Breakfast eaters did move a bit more in the morning, but they also ate more calories overall.
In other words, whether you eat breakfast is a personal choice. If you do eat it, what you eat matters far more than the timing.
How to build a breakfast that lasts until lunch
Aim to include protein, fiber and healthy fat, and to keep added sugar low. Many nutrition experts suggest 25 to 30 grams of protein at breakfast, which is especially helpful for older adults working to maintain muscle.
Easy swaps:
- Instead of sweetened cereal: Plain Greek yogurt or cottage cheese topped with berries, nuts or seeds.
- Instead of a muffin or pastry: Eggs any style with whole-grain toast and avocado or vegetables.
- Instead of flavored instant oatmeal: Plain rolled or steel-cut oats cooked in milk, topped with nuts, seeds or a spoonful of nut butter and fruit.
- Instead of a bagel with jam: Whole-grain toast with smoked salmon, eggs, or nut butter and sliced banana.
- Instead of juice: Whole fruit, which comes with its fiber.
- On busy mornings: Hard-boiled eggs, a protein-rich smoothie made with Greek yogurt or milk, or leftovers from dinner.
Read the label. Many “healthy” breakfast foods, including granola, flavored yogurt and some cereals, contain more added sugar than you’d expect. Look for options with more protein and fiber and less added sugar per serving.
One more tip for coffee drinkers
If you have low iron or are prone to anemia, consider having your coffee an hour before breakfast rather than with it. In a classic study published in the American Journal of Clinical Nutrition, drinking coffee with or after a meal reduced absorption of iron from the food by about 40%. Coffee an hour before the meal had no significant effect.
This isn’t a substitute for medical advice. If you have diabetes or take medication that lowers blood sugar, talk to your doctor or a dietitian before changing your eating habits.
Sources:
- Wyatt P, Berry SE, et al. Postprandial glycaemic dips predict appetite and energy intake in healthy individuals. Nature Metabolism, 2021.
- Leidy HJ, et al. Beneficial effects of a higher-protein breakfast on the appetitive, hormonal, and neural signals controlling energy intake regulation in overweight/obese, “breakfast-skipping,” late-adolescent girls. American Journal of Clinical Nutrition, 2013.
- Betts JA, et al. The causal role of breakfast in energy balance and health: a randomized controlled trial in lean adults. American Journal of Clinical Nutrition, 2014.
- Morck TA, Lynch SR, Cook JD. Inhibition of food iron absorption by coffee. American Journal of Clinical Nutrition, 1983.