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Abstract: >Food cues during fasting elicit Pavlovian conditioning to adapt for anticipated food intake. However, whether the olfactory system is involved in metabolic adaptations remains elusive. Here we show that food-odor perception promotes lipid metabolism in male mice. During fasting, food-odor stimulation is sufficient to increase serum free fatty acids via adipose tissue lipolysis in an olfactory-memory-dependent manner, which is mediated by the central melanocortin and sympathetic nervous systems. Additionally, stimulation with a food odor prior to refeeding leads to enhanced whole-body lipid utilization, which is associated with increased sensitivity of the central agouti-related peptide system, reduced sympathetic activity and peripheral tissue-specific metabolic alterations, such as an increase in gastrointestinal lipid absorption and hepatic cholesterol turnover. Finally, we show that intermittent fasting coupled with food-odor stimulation improves glycemic control and prevents insulin resistance in diet-induced obese mice. Thus, olfactory regulation is required for maintaining metabolic homeostasis in environments with either an energy deficit or energy surplus, which could be considered as part of dietary interventions against metabolic disorders.

Aw yes… central agouti related peptide systems must always be considered when discussing adipose tissue lipolysis. I always said that but no one would listen

Can someone translate this to layman’s for me please?

I do intermittent and extended fasts all the time. Im also around various foods all day everyday so this seems like something that effects me

It seems they were testing to see if the smell of food could trigger an uptick in metabolism during fasting, since the idea is that it makes your brain believe that it's about to be fed. Sounds like there was an increase in the break down of fatty deposits in lab rats in this study.

So, what if you try this as a weight loss aid. You smell a pizza, eat a dry salad.

At some point , will your body figure out you are crying wolf?

Thank you. That’s what I thought but wanted to make sure.

In my own experience, I’d say that it does work as they say it does. I feel the fat “melts off” more when I’m fasting around food at work VS fasting at home away from food. My mouth taste is different fasting around food VS not (I believe that’s because I’m releasing more “burned fat” during those times. Very anecdotal obviously.

Something else though. I’ve read that smelling foods can cause a spike in insulin, especially when fasting. Can both things be true?

Sounds like an idea for a follow-up study.