New laboratory research provides another reason to stay away from the cookies and punch bar this holiday season, as researchers find that merely going on a diet can feel like drug withdrawal to some.
University of Montreal researchers say the analogy to symptoms of drug cravings are in fact an appropriate description of dietary feelings because eating fatty and sugary foods causes chemical changes in the brain.
Researchers used a mouse model to study behaviors and emotions demonstrated during dieting.
“By working with mice, whose brains are in many ways comparable to our own, we discovered that the neurochemistry of the animals who had been fed a high fat, sugary diet were different from those who had been fed a healthy diet,” says Dr. Stephanie Fulton.
Fulton explained, “The chemicals changed by the diet are associated with depression. A change of diet then causes withdrawal symptoms and a greater sensitivity to stressful situations, launching a vicious cycle of poor eating.”
The research team feed one group of mice a low-fat diet and a high fat diet to a second group over six weeks, monitoring how the different food affected the way the animals behave.
Fat represented 11 percent of the calories in the low-fat diet and 58 percent in the high-fat diet, causing the waist size in the latter group to increase by 11 percent – not yet obese.
Next, Fulton and her colleagues use a variety of scientifically validated techniques to evaluate the relationship between rewarding mice with food and their resulting behavior and emotions. They also actually looked at the brains of the mice to see how they had changed.
Mice that had been fed the higher-fat diet exhibited signs of being anxious, such as an avoidance of open areas. Moreover, their brains were physically altered by their experiences.
Researchers studied the dopamine neurotransmitter. Dopamine enables part of the brain to reward us with good feelings, thereby encouraging us to learn certain kinds of behavior.
This chemical is the same in humans as it is in mice and other animals. In turn, CREB (cAMP response element-binding protein) is a molecule that controls the activation of genes involved in the functioning of our brains, including those that cause the production of dopamine. It contributes to memory formation.
“CREB is much more activated in the brains of higher-fat diet mice and these mice also have higher levels of corticosterone, a hormone that is associated with stress. This explains both the depression and the negative behavior cycle,” Fulton said.
“It’s interesting that these changes occur before obesity. These findings challenge our understanding of the relationship between diet, the body and the mind. It is food for thought about how we might support people psychologically as they strive to adopt healthy eating habits, regardless of their current corpulence.”
The study may be found online in the The International Journal of Obesity and will follow in a print edition.
Given that diets are difficult on the mind and body, experts say prevention is the best approach. Authorities recommend daily physical activity and a low to moderate caloric diet.
Source: University of Montreal