No, Walnuts Are Not the Key to Losing Weight
Walnuts already have a reputation for being healthy food, but the California Nutrition Commission wanted to know more. A new study asked whether walnuts, which are already associated with a lower risk of heart disease and type 2 diabetes, may have health benefits by altering our brains’ response to food.
Headline: Walnuts for Weight Loss? ( H e WY o g K T i m e s )
History: First, this study tested absolutely nothing with regard to weight loss. It is also worth noting in advance that it was funded in part by the California Walnut Commission, but the CWC had nothing to do with the design, execution, or publication of the study; the researchers themselves performed the research and applied to CWC for funding.
So if it wasn’t about losing weight, then what?
It was a small but dense study – double-blind and placebo-controlled. Nine obese participants were given a walnut shake or placebo (walnut-flavored and identical in calories and macronutrient breakdown) as part of their diet to maintain weight for five days. This was repeated twice, with a one-month break in between: those who received a placebo in the first round were given walnuts in the second, and vice versa. At the end of five days, subjects were asked about their hunger level, and their brains’ responses to images of food were recorded using MRI scans .
In surveys, walnut lovers reported feeling less hungry than the placebo group (which is in line with previous results from this research lab ). The brain scans were new, showing that when displaying images of high-reward food (versus low-reward food like vegetables or non-food like stones), people who drank walnuts exhibited more activity in the brain area. called an islet, which is believed to be involved in appetite and impulse control. This functional analysis of MRI, or fMRI, offers researchers a fascinating insight into brain activity, but its complex methodology has been flawed and the interpretation of fMRI results is still controversial .
Does this mean walnuts give you more willpower when faced with unhealthy foods? Not necessary. Can these results apply to lean patients other than obese subjects? I have no idea. Are walnuts special or would other nuts work? I do not know.
Okay, but how did walnuts affect the brains of these members? I would like to know as well as the researchers behind this study. This is a small step on a long road to elucidating the mechanisms behind – and the extent – of the apparent health benefits of one of the many, many foods people eat.
Takeaway: Walnuts can help you feel more satisfied and can stimulate a part of your brain that can increase your control over impulses. We can draw our own conclusions about how satiety and impulse control affect our ability to eat less, but this study is absolutely not talking about weight loss.