- A new study focused on how the body reacts to diets and lifestyle changes suggests that visual and olfactory stimuli may be a major factor in the obesity crisis.
- A “brain subnetwork” that can impact attempts at weight loss can be negatively affected by seeing or smelling foods, thus triggering overeating.
- Weight loss is of course still possible, but it may be more complicated than previously thought.
There’s a global health crisis happening right now, and no, I’m not talking about the coronavirus pandemic (though that certainly qualifies). I’m talking about the rising rates of obesity in many countries and our apparent inability to fight back against it. There have been so many studies that point out a variety of factors at play in our expanding waistlines, from more calorie-dense processed foods to lack of exercise, but a new piece of research published in NeuroImage suggests that our eyes may play a big role in why so many people keep gaining and gaining.
The study suggests that what we see on our plates or on the menu at a restaurant can dramatically affect how we feel about the food we ate, and how full we feel.
For the study, the researchers recruited nearly 100 people who were willing to undergo a dramatic lifestyle change and commit to dietary changes and regular visits to the gym to get some exercise. The volunteers underwent MRI scans to see how their brain activity related to their appetites, with follow-ups after six months.
What the scientists discovered is that sight and smell actually have a massive impact on feelings of fullness and satisfaction. The researchers suggest that this indicates that losing weight, even when a healthy diet and exercise are provided, is not just “a matter of willpower” but directly related to impulses originating in the visual and olfactory systems.
“To our surprise, we discovered that while higher executive functions, as measured behaviorally, were dominant factors in weight loss, this was not reflected in patterns of brain connectivity,” Gidon Levakov, lead author of the study, said in a statement. “Consequently, we found that weight loss is not merely a matter of willpower, but is actually connected to much more basic visual and olfactory cues.”
Visual cues in particular appear to be “an important factor triggering overeating.” Put simply, seeing the food tends to make you want to finish it, or eat as much as possible. The scientists attribute their findings to the fact that “vision is the primary sense in humans,” and that it may be particularly hard to ignore visual cues when it comes to seeing food and wanting to eat it.
This doesn’t mean that weight loss is impossible of course, and the researchers note that the “brain subnetwork” that they seem to have discovered can support successful weight loss, but other factors, like visual and olfactory cues, can sometimes work against you.