Eating Breakfast Does Not Improve Metabolism, Study Finds

Skipping breakfast is one form of intermittent fasting in which you restrict your daily eating to a specific window of time, say between 11am and 7pm, as an example. This type of eating schedule typically does promote weight loss—but what you eat is another important factor.

This is especially true if you're severely overweight and eat a standard American processed food diet. Many people find that eating breakfast leads to feeling hungry again soon thereafter, which can lead to unnecessary snacking. This is reflected in another recent study4 into the metabolic effects of eating or skipping breakfast.

As reported by Time Magazine

"...contrary to popular belief, having breakfast every day was not tied to an improvement in metabolism. Prior thought—supported by research—has shown that eating early in the day can prevent people from overeating later out of hunger, and it boosts their metabolism early. The new study which examined causal links between breakfast habits and energy balance couldn't prove that."

The study found that eating breakfast was linked to a greater overall dietary energy intake. And again, the type of foods you eat for breakfast may be the key ingredient that is being overlooked in this type of research—both past and present. Typically, you will find that eating a carbohydrate-rich breakfast will tend to make you hungry again far sooner than a low-carb, high-fat breakfast will. The reason for this is because if your body is using sugar as its primary fuel, it will need a "refill" at regular intervals, as sugar is a very fast-burning fuel.

Fat, on the other hand, is a slow-burning fuel, allowing you to feel satiated longer, and the more important fact is that you have loads more fat available than sugar stored as glycogen in your muscles and liver. While glycogen stores will only last for less than a day, your fat store can last for weeks. In addition to that, eating first thing in the morning also coincides with your circadian cortisol peak, which has an exaggerated impact on your insulin secretion. When you eat during this time, it leads to a rapid and large insulin release and a corresponding rapid drop in blood sugar levels, more so than when you eat at other times of the day.

If you're healthy, your blood sugar level won't drop dangerously low (such as can occur with hypoglycemia) but they can drop low enough to make you feel hungry again, even though you recently ate. This effect is amplified when eating a carbohydrate-rich breakfast, such as pancakes, muffins, cereal, or bread, with a large glass of juice for example.