Study finds that nuts in diet can stop kilos piling on and lower likelihood of obesity

21 Sep 2017 --- People who include nuts in their diet are more likely to reduce weight gain and lower the risk of overweight and obesity, according to a study recently published online in the European Journal of Nutrition. The findings came to light after researchers at Loma Linda University School of Public Health and the International Agency for Research on Cancer (IARC) evaluated diet and lifestyle data from more than 373,000 individuals from 10 European countries between the ages of 25 and 70.

Senior investigator Joan Sabaté, MD, DrPH, director of the Center for Nutrition, Lifestyle and Disease Prevention at LLUSPH, says that many people have historically assumed that nuts – an energy-dense, high-fat food – are not a good choice for individuals who want to lose weight. The findings, however, contradict that assumption.

“Walnuts, almonds, peanuts, pecans and pistachios are the most studied nuts for which we are certain on the health benefits,” Sabaté tells NutritionInsight of his findings. “Other nuts such as cashews, macadamias, and pine nuts are less studied but also show some health benefits.”

Nuts lead to lower weight gain
In their five-year study, Sabaté and junior investigator Heinz Freisling, Ph.D., a nutritional epidemiologist with the Nutritional Methodology and Biostatistics group at IARC headquarters in Lyons, France, found that participants gained a mean average of 2.1 kilograms during the five-year period of the study. However, participants who ate the most nuts not only had less weight gain than their nut-abstaining peers, but also enjoyed a 5 percent lower risk of becoming overweight or obese.

“To me, this confirms that nuts are not an obesogenic food,” Sabaté says.

The pair of researchers has evaluated nuts in the past and found that they are positively associated with a variety of health benefits, including healthy aging and memory function in seniors. This study, however, represents the first time they have investigated the relationship between nuts and weight on a large scale. Peanuts, which are technically a ground nut, were included in the study along with almonds, hazelnuts, pistachios and walnuts, which are classified as tree nuts.

The team analyzed information on the dietary practices and body mass indexes of 373,293 participants, working with data gathered by the European Prospective Investigation into Cancer and Nutrition. Although Sabaté and Freisling extracted and analyzed the data and reported the findings, they were joined by 35 other research scientists from 12 European countries and Malaysia who reviewed the paper ahead of publication.

Sabaté recommends that people eat nuts more often, pointing out that they offer energy, good fats, protein, vitamins, minerals and phytochemicals. He advises eating them daily in winter and less often in summer. 

“A handful a day is recommended,” Sabaté tells NutritionInsight. “The hand size relates to the body size. Thus, and a handful for you will be different for me. In dietetic terms, one to two servings per day (1 ounce = 28 grams is one serving). The FDA issued a health claim on nuts and cardiovascular disease, and recommended 1.5 ounces per day.”

Most nuts are a good source of mono-unsaturated fats, which are a shelf-stable fat, Sabaté adds. “Nuts can be consumed not only as snacks or in baked goods, but at the ‘center of the plate.’ Given their high protein and fat content, they are very satiating. They can totally or partially replace high-protein and high-fat animal foods such as meats and cheese in the diet.”

The findings are consistent with a recent California Walnut Commission-supported study which found that walnuts activate the brain area that controls the appetite. Other potential benefits include activating the body's own defenses for detoxifying reactive oxygen species and protective effects against colon cancer. 

By Paul Creasy