Eating walnuts may help control appetite

Boston: Munching on walnuts may help control hunger pangs, according to a study which found that the snack activates an area in the brain associated with regulating appetite. “It was pretty surprising to see evidence of activity changing in the brain related to food cues, and by extension what people were eating and how hungry they feel,” said Olivia M Farr from Beth Israel Deaconess Medical Center in the US. Researchers used functional magnetic resonance imaging (fMRI) to observe how consuming walnuts changes activity in the brain. They recruited 10 volunteers with obesity for two five-day sessions. A controlled environment allowed researchers to keep tabs on the volunteers’ exact nutritional intake, rather than depend on volunteers’ often unreliable food records. During one five-day session, volunteers consumed daily smoothies containing 48 grammes of walnuts — the serving recommended by the American Diabetes Association dietary guidelines. During their other stay in the clinic, they received a walnut-free but nutritionally comparable placebo smoothie, flavoured to taste exactly the same as the walnut-containing smoothie. Researchers noted that participants reported feeling less hungry during the week they consumed walnut-containing smoothies than during the week they were given the placebo smoothies. While in the machine, participants were shown images of desirable foods like hamburgers and desserts, neutral objects like flowers and rocks, and less desirable foods like vegetables. —