Slow Down to Smell the Roses; Better Yet Sniff This to Curb Hunger

A huge chunk of taste actually relies on your sense of smell.  Smells can bring back memories (good or bad), make you nauseous or hungry.

But could we use smell to help you make better decisions as it relates to your appetite and subsequent body weight?

There are regions of the brain that relate to hunger and satiety (your sense of fullness).  Specifically, the lateral hypothalamus, when stimulated by increased blood flow, stimulates hunger and eating.  The anterior insula region of the brain, when stimulated, prompt you to eat more.  Research has shown that high fat meals reduce the activity of the lateral hypothalamus and thus make you feel more full.  Low fat meals, on the other hand, stimulate blood flow to the anterior insula, leading you to reach for seconds.

If the high fat foods themselves have this effect on hunger and appetite, what about just the aroma of high fat foods themselves such as olive oil?  That’s exactly the question that was asked in this particular study.

Researchers took a small group of 11 participants and fed them one of two meals: a low fat yogurt and a low fat yogurt that was infused with the aroma of olive oil.  During each meal, they were put under functional MRI, which looks at blood flow to regions of the brain in real-time.  Here’s what happened:

  1. There was higher blood flow in the insula 30 and 120 minutes after a meal with the olive oil aroma.
  2. After 30 minutes of the aroma meal, any increases in blood flow to the anterior insula were associated with higher levels of blood sugar.
  3. No changes were observed in the hypothalamus.

Overall, while a little complicated, the results basically suggest that we may be able to use aromas that merely remind us of fattier meals to trigger the same effects on feeling full, thus making it easier to eat lower calorie meals.

However, don’t let this deter you from taking in your fill of healthy fats such as wild caught fish, avocados and raw nuts.  These fats do not contribute to weight gain.


James Bogash

For more than a decade, Dr. Bogash has stayed current with the medical literature as it relates to physiology, disease prevention and disease management. He uses his knowledge to educate patients, the community and cyberspace on the best way to avoid and / or manage chronic diseases using lifestyle and targeted supplementation.