It was further found that most of the weight lost was fat, with the mice burning brown fat, which burns energy and keeps us warm, and then turning unhealthy white fat into brown fat and burning that.
Researchers at the University of California, Berkeley, fed the same high-fat diet to two groups of lab mice - some that could smell and some that could not.
The findings suggest that the odor of what we eat may play an important role in how the body deals with calories. Researchers say there's a key connection between the body's smell system and parts of the brain that regulate metabolism. People are more sensitive to smells when they're hungry than after they've eaten, and those who lose their sense of smell - because of age, injury, or disease - often become anorexic. The lack of food smells could trick the body into thinking it's already eaten, so it burns calories instead of storing them. It's unclear if the same would work on humans.
In the second mouse model, his team ablated olfactory sensory neurons using an inhaled virus, producing a similar loss of olfactory sensory neurons with a lower chance of affecting cells outside the olfactory system.
UC Berkeley, the Max Planck Institute for Metabolism Research, Germany, and the Salk Institute for Biological Sciences, California, researchers conducted this study. "If we can validate this in humans, perhaps we can actually make a drug that doesn't interfere with smell but still blocks that metabolic circuitry". These mice became obese, but not because of food consumption.
In fact, they said, it seems that weight gain is linked to the way calories are perceived. Namely, they presented an increased fat burning activity, as their white fat was transformed into brown one.
"People with eating disorders sometimes have a hard time controlling how much food they are eating and they have a lot of cravings", Riera said.
Intriguing sidenote: Dillin mentioned his results to a German scientist who'd bred a "super-smelling mouse" (scientists do weird stuff), which put on even way more weight than a regular-smelling mouse despite eating the same amount. The weight that they lost came only in the form of fat, not organs, muscles or bone mass.