Already deciding whether to get pizza or Mexican for lunch, even though you’re still chewing the last remnants of breakfast? Don’t worry; this is actually quite normal. There are good reasons why you may be getting ravenously hungry only minutes after your last meal.
First, it’s important to understand that if you fill your stomach too quickly, your body won't have time to recognize and comprehend messages from specific hormones that help control appetite. “Hormones such as insulin, leptin, cortisol, and ghrelin send signals between the stomach and the brain indicating hunger, but also indicating satiety,” explains Dr. Robert Glatter, attending physician in the Department of Emergency Medicine at Lenox Hill Hospital in Manhattan, New York. Although you may feel your stomach filling up when you eat, it typically takes around 15-20 minutes to digest food to the point that glucose (sugar) gets into the bloodstream and the hormones begin functioning. “As a result, if you have already eaten most of a meal in about 20 minutes, your brain will not be able to slow your eating because it will receive satiety signals too late,” says Glatter.
What are the best foods to keep us satiated and not ransacking the fridge? “Fiber-rich carbs and lean protein foods are satisfying because they digest slowly, so they remain in the stomach longer and stabilize blood sugar levels, which help reduce sugar cravings,” says Tanya Zuckerbrot, registered dietician and the creator of the renowned F-Factor Diet.
Of course, it’s tempting to opt for a convenient quick-fix solution such as a muffin or bag of chips, but foods containing fat aren’t actually satiating. “Fat tastes good, but does not fill you up. Satiation is actually more defined physiologically,” says Glatter.
“The ideal meal to promote satiety should include a small amount of fat, a lean source of protein, and a variety of fiber-rich fruits, vegetables, and whole grains.”
Of the three food groups — protein, carbohydrates, and fats — protein is the most satiating. About 25 to 35 percent of protein calories are used as the body converts protein to energy; only five to 15 percent are used when carbohydrates are converted. “Researchers aren't quite sure, but a specific component in protein serves as a signal to stop eating,” says Glatter. “The mechanism is likely related to protein’s high thermic effect, which is the rate at which these calories are consumed as part of the digestion. It turns out that the digestion and absorption of protein takes more work or calories than the digestion and absorption of carbohydrates and fat.”
Carbohydrates are the next most satiating foods. The satiating effect of carbohydrates depends on the type of carbohydrate being consumed. Whole grains (e.g. barley, brown rice, and whole wheat bread) are more satisfying than refined sugars and refined white flour. “Whole grains are more filling because they contain higher amounts of fiber. Unlike other foods, fiber is not digestible. Fiber adds bulk to foods, which helps fill the stomach, slowing the rate at which food is digested. As a result, you feel fuller sooner,” says Dr. Glatter.
Fruits and vegetables contain high percentages of water, air, and fiber, and generally have a lower energy density (the number of calories per gram) than meats, dairy items, and sweets. In other words, you get to eat more of them without the consequences that high-calorie foods can bring. “A number of studies have demonstrated that eating salads can help people eat less without feeling deprived,” explains Glatter. “Eating a salad prior to a meal can increase satiety such that some people will eat up to 10 percent less food during a meal.”
Check out our expert-recommended suggestions for foods to keep you feeling fuller for longer.
Black Beans and Pinto Beans
“Legumes such as black beans and pinto beans, in my mind, are such an underrated food. Not only are they packed with plant-based protein, fiber, and phytochemicals, they’re also really easy on the wallet. A 2008 study in the FASEB Journal found that eating at least ½ cup of legumes per day may assist with weight loss and weight maintenance, perhaps due to increased sense of fullness.”
— McKenzie Hall, registered dietician and co-founder of Nourish, which aids with recipe or menu development, nutritional analysis, social media, research briefings, and consumer information.
“These tiny nutrition powerhouses contain about 10 grams of fiber per two tablespoons and are an excellent source of important omega-3 fatty acids. They are also a good source of essential nutrients like iron, calcium, magnesium, and zinc. In addition, chia seeds have hydrophilic properties. This allows them to swell into a gel when combined with liquid. The combination of high fiber (which digests more slowly in the GI tract and keeps blood sugar levels stable) and the hydrophilic properties (which result in them expanding in the stomach to give the feeling of fullness) make this a top-pick food to keep you full. Try them on yogurt, soups, baked goods, in smoothies, or make your own chia gel.”
This article originally published on January 13, 2015.