Background: Consumption of nuts and peanuts in the USA has increased over the years. However, there has been little proof of the association between the change in nut consumption and long-term changes in weight. Researchers from Harvard University investigated the facts in 2019. To achieve this, data from three independent cohort studies were evaluated:

• 27,521 data sets from men who took part in the “Health Professionals Follow-Up Study” from 1986 to 2010.
• 61,680 data sets from women who took part in the “Nurses Health Study” from 1986 to 2010 and
• 55,684 data sets from younger women who took part in the “Nurses Health Study II” from 1991 to 2011.

All participants were free of chronic disease at the beginning of the study (baseline).

The researchers investigated the association between changes in nut consumption over four-year intervals and concurrent weight changes over 20 – 24 years. 21,322 people attained a high body mass index (BMI ≥ 30 kg/m²). People are classified as obese once they reach a BMI of 30 kg/m² and above. Average weight gain across the three cohorts was 0.32 kg per year. Consumption of nuts increased, on average, by 14 g per day.

From the data, the researchers were able to determine that long-term weight gain decreased in negative correlation with the amount of nuts consumed, including peanuts: in other words, the more nuts you consume, the less weight you gain.

Synopsis of the study: Increasing your daily consumption of nuts and peanuts may be associated with decreasing the risk of moderate weight gain and lowering the risk of becoming obese. Integrating nuts into your diet as part of a healthy lifestyle can be an effective strategy for primary prevention of obesity.