Legumes Really Satisfy

Legumes, which include beans (such as red beans, navy beans, soy beans), lentils, peas, and edible pods (such as okra, snap peas and snow peas) are one of the nine tenets of the Mediterranean Diet. We know that adding legumes to your diet helps you reduce your risk of heart disease and colon cancer, helps improve cholesterol scores, and can even help you improve your blood pressure. They're high in fiber, which makes them especially satisfying, and we know that more fiber in your diet can help you avoid gaining weight (Bite, 07/12/06).

Researchers in Toronto, Canada (Brit J Nutr doi:10.1017/S0007114511005836) noted that although legumes themselves are low-glycemic-index foods, they are often eaten with high carbohydrate foods such as rice, pasta or bread. Would eating a legume-rich meal have an effect on how much a person ate at that meal - and how would their blood glucose be affected afterwards? Would eating such a meal have an effect on how much a person ate later in the day?

To find out, they recruited 26 healthy, normal-weight men between the ages of 20 and 30 to participate in a feeding study. Each man came into the lab once per week for five weeks and were fed a standard breakfast, then one of five lunches, then unlimited amounts of pizza for dinner. The test meals were the lunches, which all contained the same number of calories. The control meal was a simple pasta with tomato sauce. The other four test meals added pureed legumes to the pasta sauce, while reducing the amount of pasta to adjust for the added calories. The four legumes used were chickpeas, lentils, navy beans or yellow peas.

The researchers were able to measure how much the participants ate, both at the test lunches and at the dinner meals following, to see if what they ate for lunch had any effect on how much they ate at dinner.

Each participant answered questions about how hungry they were before, after, and at regular intervals up to and after the unlimited pizza dinner. Their blood glucose was monitored at regular intervals as well.

The researchers found that all of the pasta meals that included legumes all led to lower post-meal blood glucose levels than the comparison meal that did not include legumes. Chickpeas had the greatest effect, extending their blood glucose effects to the pizza meal later in the day. On the other hand, the pasta meal that included lentils led to the subjects eating less pizza later.

What this means for you

Legumes are great for you, satisfying for the long term, and appear to help reduce that post-meal spike in blood glucose. We can only conclude that you should eat more legumes! Here are some recipes to try:

Lentil Chili
Red Beans and Rice
Lentil and Black Bean Salad
Cannellini Bean Soup
Corn and Black Bean Taco Salad

First posted: November 9, 2011