Source: Cell Press
Summary: Researchers show that the reward center of the brain values foods high in both fat and carbohydrates i.e., many processed foods – more than foods containing only fat or only carbs.
After the domestication of plants and animals and the development of grain and dairy production around 12,000 years ago, opportunities to consume fat and carbohydrates together increased, but processed foods like donuts, which could contain 11 grams of fat and 17 grams of carbohydrate, have only been around for 150 years, not long enough for us to evolve a new brain response to them. Scientists believe our past experience with the nutritive properties of carbohydrates releases dopamine in the brain through an as-yet-unknown metabolic signal. These kinds of signals seem to help regulate what and how much we eat. Researchers show that the reward center of the brain values foods high in both fat and carbohydrates i.e., many processed foods – more than foods containing only fat or only carbs. The study findings were published in the journal Cell Metabolism.
A study of 206 adults, supports the idea that these kinds of foods hijack our body’s inborn signals governing food consumption. In work that could help explain brain-body mechanisms underlying the genetic predisposition for obesity, eating in the absence of hunger, and difficulty losing or keeping off excess weight, researchers looked at the neural response to food cues. Test subjects underwent brain scans while being shown photographs of familiar snacks containing mostly fat, mostly sugar, and a combination of fat and carbs. The researchers theorize that the simultaneous activation of fat and carbohydrate signaling pathways launches an effect that human physiology has not evolved to handle.
Senior author, Dana Small said, “The biological process that regulates the association of foods with their nutritional value evolved to carefully define the value of a food so that organisms can make adaptive decisions.”
More Information: Cell Metabolism, DiFeliceantonio and Coppin et al, “Supra-Additive Effects of Combining Fat and Carbohydrate on Food Reward”, Cell Metabolism (2018). DOI: 10.1016/j.cmet.2018.05.018