The secret to feeling fuller longer isn’t some magic serum you place under your tongue to subdue your hunger or eating super-dense meal replacement bars either. The answer is high-fiber foods. 

Fiber in general keeps you full simply because we lack the enzymes to break it down. It acts as a sort of sponge, absorbing water and forming a gel-like texture in the stomach, which slows the passage of food throughout your intestine, says Jim White, R.D., Academy of Nutrition and Dietetics spokesman, owner and president of Jim White Fitness & Nutrition Studios. "Digestion is slowed and blood sugar levels are also stabilized," he adds. "Slower digestion means less hunger, which can help when you're implementing a lower calorie diet for weight loss."

But that's not all fiber can do for you. Getting the right amount of fiber from breads, cereals, and fruits can help you avoid disease and disability as you age, according to brand new research from The Gerontological Society of America. Fiber is the most important component to "successful aging."

"Essentially, we found that those who had the highest intake of fiber or total fiber actually had an almost 80 percent greater likelihood of living a long and healthy life over a 10-year follow-up," lead study author Bamini Gopinath, Ph.D. said in a press release. "That is, they were less likely to suffer from hypertension, diabetes, dementia, depression, and functional disability." You can tack on cancer, heart disease, and stroke, too. 

Generally you want to get your base of 25-45 grams of fiber per day in the form of whole grains, vegetables, and fruits, White suggests. Here are 15 high-fiber foods that will help regulate your appetite and metabolism, and keep you feeling young well into your Golden Years.