Have you ever eaten a decent-sized meal and then felt hungry soon after? How could that happen? It certainly seemed like you were eating enough to feel satisfied and energetic for the next several hours.
The likely answer: It’s what, not how much you ate that’s to blame.
Let’s say your meal was a typical offering from a fast-food restaurant. Its main constituents of processed carbohydrates and unhealthy fats are hallmarks of the standard American diet (which we like to call “SAD,” but, as far as your body is concerned, these are definitely not happy meals).
When your body starts to process this high-sugar/high-fat meal, your digestive system releases a hormone known as glucose-dependent insulinotropic polypeptide, or GIP. As GIP goes to your brain, your normal metabolism of leptin, a hormone associated with feeling satiated, is affected. Specifically, the release of leptin into your bloodstream is dramatically curtailed. One important consequence of both GIP release and leptin production gone haywire is that your body braces for a rush of carbohydrates, and prepares to deal with a sudden rise in your blood glucose (what you might call “blood sugar”) by loading insulin.
The graphs below illustrate this harmful process. In these graphs, the blue/red line represents your blood glucose (BG); the line is blue when BG levels are within your body’s preferred range, and red when they’re not. The white bar represents the amount of time after your SAD meal.
There are also long-term effects from SAD meals to consider. Any one meal might not cause a particularly severe boom and bust of your BG levels. But over time, the constant swings can take a toll, and can lead to increased fat storage and the development of chronic conditions such as type 2 diabetes.
Put another way, conventional nutrition tends to look at the contents of your daily diet mostly through the lens of whether you’re getting adequate vitamins and minerals. There’s not as much attention given to how regular insults to your body’s energy-management system can wreak havoc on that system and, eventually, your health.
What’s a better approach? The graph below illustrates what happens to BG levels in the two hours after a breakfast of ricotta cheese and raspberries.