Eating one serving (3/4 cup) of beans, peas, lentils or chickpeas every day may help dieters lose a little extra weight, according to a new analysis of existing research from St. Michael's Hospital in Toronto.
Researchers examined data from nearly two dozen trials and found that participants who ate about three quarters of a cup of legumes every day lost about three quarters of a pound more than those who didn’t eat legumes, regardless of whether the diets were geared to weight loss.
Legumes - or pulses, as they are known in many parts of the world - are an important sustainable protein source, plus they’re high in fibre.
Pulses also have a low ‘glycemic index,’ which means the carbohydrates in them do not raise blood sugars as rapidly as things like white bread or white flour.
Previous studies have found that eating foods high in fibre and protein and low in the glycemic index promote weight loss, but the specific role of legumes hasn’t been clear.
The researchers culled 19 studies, based on 21 clinical trials that compared the effects of diets containing legumes with diets that didn’t include legumes, but had the same number of calories.
Only four of the studies were designed as weight loss studies; the remainder were meant to study weight maintenance. A total of 940 obese or overweight adults participated in the trials, which lasted from four to 12 weeks.
Eating pulses daily show promise, in particular, for maintaining a weight loss
After an average of six weeks, the study participants who ate legumes every day lost about 0.34 kilograms (0.75 lb) more than those who didn’t.
“Though the amount of weight loss was small, it's important to state that the pulse-containing diets we reviewed were not designed for weight loss,” the lead researcher said.
Six of the trials also suggested that eating legumes was linked to slightly lower body fat, though there was no evidence of a difference in waist circumference.
Swapping legumes for other sources of protein, such as meat, may be a painless way to eat healthier and lose a little weight.
A previous study conducted by the Toronto researchers found eating pulses may help with appetite control - eating 100 calories worth of pulses at a meal will make you feel about one-third more full than 100 calories from another food.
Losing weight is relatively easy but keeping it off is much, much harder. The researchers feel this is where eating more pulses in your daily diet can really help.
There were some limitations to the study. Many of the trials were short-term and not of the highest quality. The authors also couldn’t tell what the long-term effects of eating legumes would be.
Other reasons to eat more beans and lentils
Beyond weight control, there are many nutritional benefits to eating legumes regularly. Pulses are loaded with antioxidants and phytochemicals that can help protect against cancer and cardiovascular disease.
The fibre in beans and lentils helps lower levels of LDL (bad) cholesterol in the blood. As well, they are high in potassium and magnesium, minerals that help keep blood pressure in check.
For people who are not accustomed to eating beans, adding about a half cup per day is a good place to start, she said, adding that they can be used in place of other starches like potatoes or rice.
Other easy ways to include them to your diet: add cooked lentils and beans to salads, soups and stews.
All research on this web site is the property of Leslie Beck Nutrition Consulting Inc. and is protected by copyright. Keep in mind that research on these matters continues daily and is subject to change. The information presented is not intended as a substitute for medical treatment. It is intended to provide ongoing support of your healthy lifestyle practices.