If you're looking for a healthy snack, nuts may be a sure-fire try. The latest study published in the journal BMJ (British Medical Journal) Nutrition, Prevention & Health suggests that just half a serving (½ oz) of nuts a day is linked to less weight gain and a lower risk of obesity.
About the study
In this large-scale observational study, the researchers analyzed information in three groups of people for more than 20 years:
—51,529 male health professionals, aged 40 to 75 when enrolled in the Health Professionals Follow Up Study
—121,700 nurses, aged 35 to 55 when recruited to the Nurses’ Health Study (NHS)
—116,686 nurses, aged 24 to 44 when enrolled in the Nurses’ Health Study II (NHS II).
Every 4 years, the participants were asked to state their weight, and how often they had eaten a serving (1 oz) of nuts, including peanuts and peanut butter.
It turned out that increasing daily consumption of any type of nut was associated with less weight gain and a lower risk of obesity.
Specifically, within any 4-year period, increasing daily nut consumption from none to at least half a serving was associated with a lower risk of moderate weight gain, and a 16% lower risk of obesity, compared with not eating any nuts.
Besides, eating at least half a serving of nuts daily for a long time was associated with a 23% lower risk of putting on 5 or more kilos and obesity over the same timeframe.
After taking account of lifestyle changes including exercise and alcohol intake, the findings still held true. But such associations were not found in peanut butter intake.
Why this would happen
The researchers suggest that there may be several reasons:
—Chewing nuts takes some effort, leaving less energy for eating other things
—Eating nuts rather than biscuits or crisps can help prevent the weight gain and obesity
—The fiber of nuts can bind well to fats in the gut, consuming more calories
—The high fiber content of nuts can delay stomach emptying, making a person feel full for longer time
—The high unsaturated fat content of nuts can increase resting energy expenditure, contributing to less weight gain
Eating nuts can even bring benefits to the planet. "In addition to the impact on human health, using environmentally friendly plant-based protein, such as nuts and seeds to replace animal sources of protein may contribute to the promotion of a global sustainable food system," the researchers wrote.