What do people binge eat, lose control over? What do they have such intense cravings for that they find it difficult to stick to their own dietary goals? It isn’t fruits or vegetables like apples or carrots, which isn’t surprising. Although kale was not high on the list, delicacies like cupcakes and ice cream were. So that is what we concentrated on here. And one of the most common responses I receive when I tell people I perform research on food. And addiction is, “How can you addicted to food?” Right?
Everyone must eat; what is the abstinence method, starvation? I think it’s important to remember that we’ve always said that not all foods created equal. That there are certain foods that aren’t good for our long-term health and survival. That those are the same foods that seem to be particularly effective at manipulating our reward systems in a negative way.
So, if you think about the food environment in which we evolved. Especially high-calorie foods, were relatively scarce, and the foods at the top of that hedonic ladder that were really rewarding. Reinforcing were foods like fruits and nuts, which had higher levels of fats and sugars in them. We are evolutionarily design to want to seek out and find those f
We then blend them into thousands of other food types. All of which are heavy in carbohydrates, fats, salts, and food additives. To give you an idea of how different our food environment. Is now compare to the food environment in which we developed. When I first started doing this research. We discovered that there aren’t many naturally occurring foods that are high in both carbohydrates and fat. You have fruits, are heavy in sugar but low in fat, and you have items, such as nuts and meats. Which are high in fat but low in carbohydrates.
The fact that the majority of the foods we eat today in our food environment. Contain a combination of high fat and high carbohydrate levels is a food that is unique to our brain’s reward system and far more potent than anything our brains have evolved to handle.
So, have these meals got so robust and effective that they are capable of generating an addictive response in at least some people?
We found a lowering of the dopamine system in response to diets heavy in fats and sweets. Which was associate to behaviors that we thought were symptomatic of drug misuse or addiction to substances of abuse. One example from Paul Kinney’s lab was that rats who were expose to foods like bacon and cheeseburgers, as well as M&M’s. Became so accustomed to that level of hedonic food reward that, even though they had their usual chow. Which they usually ate just fine, they were usually motivate by, right next to them in their cage, that food. After being expose to these highly rewarding foods, no longer did.
Even though they could consume those calories. They would venture into electrified mazes, where they would jolted, in order to locate the M&Ms buried within the maze. So, at least in these animal models. It appears that exposure to these foods that are so potently gratifying may trigger neural modifications to our reward and motivation systems in the brain to the point where other naturally occurring foods that we used to like and eat just fine can’t compete. Simultaneously, I was doing some amazing neural imaging work that showed commonalities in the neural systems that appear to go awry in the contexts of obesity and addiction.
Someone mentioned that when traveling down the highway and seeing the golden arches. These cues can become quite powerful, capable of eliciting acute dopaminergic responses connected to hunger and motivation in both obesity and addiction. There also appears to be a loss of capacity in the brain’s cognitive control processes. Causing people to become more reactive and motivated to the stimuli in their surroundings while also unable to put the brakes on.