Weight Loss Food? I'm Listening...
You probably read "weight loss food" and got a little excited. After all, everybody wants to eat something that helps them lose fat. But you're also probably a bit skeptical.
That's understandable, but the food I'm talking about really is something to get excited about, even though its very name screams ordinary and dull. The food is... beans.
Beans? Yep. A recent study of 246 subjects found that regularly adding some beans to the diet was related to less body fat and smaller waists than low bean intake.
Before getting into the particulars of the study, let's first look at why eating beans regularly or semi-regularly was associated with better bodies. The authors of the study thought there were at least six contributing factors:
- According to US dietary guidelines, beans are the only food that gets dual classifications as both a vegetable food and a protein food. Protein is the most filling of the three macronutrients, so bean eaters typically end up eating less of other foods.
- While beans are a nutrient-dense food, they're not a calorie-dense food.
- Beans are among the lowest glycemic-index foods. Compared to other foods, beans cause less of a rise in blood sugar levels.
- Beans contain a lot of dietary fiber, with one cup containing approximately 10 to 16 grams. Fiber, particularly soluble fiber, binds up fats and sugars, leading to reduced absorption in the digestive tract.
- One study (Reverri et al.) found that black beans increase cholecystokinin and peptide tyrosine tyrosine (PYY), which are satiety-increasing hormones. Again, the more full you feel, the less you're inclined to calorie-up on other foods.
- Beans have a favorable impact on the intestinal microbiota and a healthy gut plays a part in body weight and adiposity.
In short, "beans possess a unique combination of dietary qualities."
The study involved 246 women, though we can assume the results for men would be similar. Each participant was asked to fill out the lengthy "Block Food Frequency Questionnaire," considered by dietary experts as a legit and reliable instrument for assessing dietary intake.
The questionnaire is eight pages long and even contains four specific questions about the types of beans and legumes ingested: (1) refried beans or bean burritos; (2) chili with beans; (3) baked beans, pintos, or other dried beans; and (4) bean, split pea, or lentil soup.
Participants were asked to indicate how much and how often they ate those items, and the results were used to calculate total annual consumption.
They compiled all the stats and compared the top third of bean eaters with the bottom third of bean eaters. They found a mean body fat difference of almost 4 percentage points and an average waist size difference of about 4 centimeters (one and a half inches).
The researchers considered physical activity, too, as each participant was required to wear an "accelerometer" on their hip to measure how much they moved. Those results, along with age and education, were considered "covariates" and were included in their analysis of the results.
Phaseolus vulgaris, aka the common bean, includes a whole lot of different varieties of bean, including:
- Kidney beans
- Snap beans
- Pea beans
- Wax beans
- Northern beans
- Haricot (navy) beans
- Field beans
- Black beans
All of them should pretty much have the same beneficial dietary attributes, so feel free to avoid any that taste yucky to you.
How many should you eat, and how often? There's no magic, precise number. The women in the study were by no means consciously including beans in their diets to lose weight, but their yearly mean bean and legume intake was around 50 cups.
Obviously, some ate a serious amount of beans while others apparently would not eat them in a box, not with a fox, nor in a house, or with a mouse.
However, based on the results of this study and others, including a small amount of beans (1/2 to 1 full cup) in 3 to 7 meals a week would make a noticeable difference in body composition over the course of months.
Make soup or chili with them, add them to salads, or just use small amounts of canned varieties as side dishes.
- Tucker LA. Bean Consumption Accounts for Differences in Body Fat and Waist Circumference: A Cross-Sectional Study of 246 Women. Journal of Nutrition and Metabolism. 2020:Article ID 9140907. PubMed.