What Happens to Your Blood Sugar When You Skip Breakfast

While blood sugar management is top of mind for people with diabetes, everyone can benefit from having stable blood sugar levels, whether they have diabetes or not. Taking steps to avoid blood sugar spikes (and crashes) can support your overall energy and metabolic health. And while you might think that skipping breakfast will help keep your blood sugar stable, the opposite is actually true. 

When you skip your morning meal, your body is more likely to experience bigger swings in blood sugar later in the day, and you may experience more intense cravings and energy dips that can make it difficult to manage your appetite. “How you start the morning sets the tone for your energy, hunger and cravings for the rest of the day,” says Madison Reeder, RD. 

Here’s why starting your day with a balanced breakfast supports better blood sugar management and metabolic health. 

Why Breakfast Is Important for Blood Sugar 

Regularly eating breakfast is linked to a reduced risk of diabetes and better blood sugar management. Here’s how.

It Can Improve Insulin Sensitivity

How well your cells react to insulin determines how easily and efficiently glucose is shuttled from your bloodstream into your cells for energy. “When you skip breakfast, your body stays in a prolonged fasting mode and becomes less sensitive to insulin,” says Reeder. 

As the body breaks down lipids for energy during extended fasting, higher levels of free fatty acids in the blood can disrupt insulin receptors from working properly, which can lead to higher blood sugar levels after meals. Researchers suspect that skipping breakfast may also interfere with the body’s circadian rhythm, which helps to regulate insulin secretion and other factors impacting blood sugar.

It Helps You Eat More Fiber

Including fiber with your meals not only helps you feel more full and satisfied, but it can also have a substantial effect on your blood sugar. One study found that diets high in fiber may lower HbA1C by an average of 0.66% and reduce fasting glucose and fasting insulin levels.

“People who eat breakfast get more fiber and essential nutrients and consume less added sugar over the day,” says Reeder. And while some research suggests that skipping breakfast could result in a reduced calorie intake of around 250 calories per day, the reduction in daily diet quality is likely to have a negative impact on health over time. Breakfast skippers tend to eat less fruit and whole grains, both of which are significant sources of fiber in the diet.

It May Reduce Cravings and Overeating

Eating a larger meal for breakfast can help you feel less hungry as the day wears on. Skipping breakfast decreases leptin (the hormone that helps you feel full) and increases ghrelin (the hormone responsible for hunger) which can lead to feeling hungrier and less satisfied when you do eat. “This ‘feast or famine’ pattern can make you more likely to grab something quick and high-carb by late morning, sending your blood sugar on a roller coaster of spiking and crashing,” says Reeder. 

It Supports Better Metabolic Health

“Breakfast eaters tend to have healthier weights and a lower risk of developing type 2 diabetes compared to those who frequently skip the morning meal,” says Reeder. According to a large systematic review, people who skip breakfast are 48% more likely to be overweight or obese and 31% more likely to have abdominal obesity than those who regularly eat breakfast.

And if you have type 2 diabetes, eating breakfast could provide major improvements, as skipping breakfast is related to higher A1C levels, a measure of long-term blood sugar control.

How to Build a Blood Sugar–Friendly Breakfast 

While breakfast itself is associated with better blood sugar management, not all meals are created equal. To make the most of your morning meal, follow these steps. 

Start with Fiber-Rich Carbs

Whole grains and fruit are rich in carbs, but they’re also high in fiber, which helps slow down the absorption of glucose and supports a healthy gut microbiome. Instead of lower-fiber refined carbs like high-sugar cereal and pastries, choose whole-grain bread, oats or even baked goods made with whole-grain flours. For natural sweetness and an antioxidant boost, add fiber-rich fruits like berries, apples, pears and cherries to your plate. 

Add Protein

Protein helps you feel full while also slowing down the digestion of glucose, helping to avoid spikes and promote longer-lasting energy. One study found that a high-protein breakfast can suppress post-meal blood sugar levels compared to eating a low-protein breakfast.

Easy ways to add protein to your morning meal include low-fat yogurt or cottage cheese, lean meats, eggs, legumes, nuts and seeds. Mix strained (such as Greek-style) yogurt into a parfait, stir nut butter into oatmeal, or toss some beans into a breakfast burrito to make your meal more filling and blood sugar–friendly. 

Include Healthy Fats

Fats also slow digestion, which helps keep your blood sugar stable while adding flavor and satisfaction to your meal. Prioritize unsaturated fats, which support heart health and may offer some protection against insulin resistance. Top toast with avocado, add nuts or seeds to oatmeal, or cook your eggs in olive oil for a boost of healthy fats. 

Other Tips for Supporting Healthy Blood Sugar Levels  

• Eat at regular intervals: Avoid going too long between meals to prevent extreme hunger and blood sugar dips and spikes. “Regular meals keep glucose entering the bloodstream in steady amounts, which helps your body use insulin more efficiently,” says Reeder. 
• Be mindful with portions: How much you eat can be just as important as what you eat for managing your blood sugar. “A large amount of carbs at once can overwhelm your system, causing a surge in blood sugar,” says Reeder
• Walk after eating: Even just a few minutes of activity after a meal can lower blood sugar and prevent spikes.
• Prioritize sleep and stress management: Skimping on sleep and letting your stress get out of control can put your body in a chronic state of “fight or flight,” “Poor sleep and chronic stress both make your cells less responsive to insulin, which raises blood sugar,” says Reeder. 

Our Expert Take 

Making time for a balanced breakfast supports energy levels, focus and steady blood sugar levels throughout the entire day, long after you’ve taken your last bite. “Breakfast can be one small but important step in protecting your metabolic health over time,” says Reeder. To make the most of your breakfast, balance fiber-rich carbohydrates, protein and healthy fats to keep your energy stable, reduce cravings and support long-term health.