Smelling meat can make you lose weight? Sub-journal of Nature: Smell therapy can promote lipid metabolism and lose weight easily

You who have been struggling to lose weight,

< span> What weight loss methods have you tried?

Diet, weight loss products, exercise…

With the emergence of many weight loss methods, a new smell weight loss method has begun to enter the public Scientists have even developed some compound odor products. The mixed smell of mint + a little pepper will make the brain have the illusion of “eat full” and suppress appetite; the smell of some essential oils not only relieves stress and boosts the spirit, but can even cure edema-type obesity by promoting metabolism. So how exactly does smell affect fat metabolism?

Actually, the sense of smell The association between fat metabolism and fat metabolism is not a new thing, but scientists have not been clear about the mechanism behind this phenomenon. On November 14, 2022, the team of Professor Toshiyasu Sasaoka from the Department of Clinical Pharmacology, Toyama University, Japan, was inNature Metabolism New Research Publishes Answers to the Link Between Smell and Fat Loss. In simple terms, smelling food during fasting can promote lipid metabolism in the body; when intermittent fasting is combined with food odor stimulation, it can control blood sugar levels and prevent insulin resistance .

Image source: Nature Metabolism

1 Perception of food odors promotes mobilization of non-esterified fatty acids during fasting.

In the early stage of the experiment, the mice relied on their sense of smell to explore high-fat food. By cutting off the olfactory bulbs, it was found that the mice that lost their sense of smell stopped exploring based on their odor preference, and the visual stimulation of food had no effect on the behavior of the mice.

Figure 1. Fasted mice explore food based on olfactory rather than visual information. (Image source: Nature Metabolism)

The main source of energy during fasting is adipose tissue breakdown which increases serum free fatty acids. Under 24-hour fasting conditions, normal chow (NCD) odor stimulation further increases serum levels of non-esterified fatty acids (NEFA), especially Increased levels of oleic and linoleic acids and decreased palmitic/oleic and stearic/oleic ratios. The above results are favorable because unsaturated fatty acids are beneficial for metabolic health.

Figure 2. Changes of NEFA levels in fasted C57BL/6J mice exposed to food olfactory or visual information for 1 hour. (Image source: Nature Metabolism)

2 The mechanism of lipid mobilization by food odor

Research has found that the hypothalamic melanocortin 4 receptor (MC4R) and the sympathetic nervous system are involved in this process. By analyzing protein and gene expression profiles, it was found that 10 min of odor stimulation during fasting enhanced lipolysis in adipose tissue and increased phosphorylation of S6 ribosomal protein, a molecule downstream of mTOR, in the liver. Gene expression in the soleus muscle, epididymal white adipose tissue (eWAT), and pancreas was also affected by olfactory stimuli one hour after odor exposure.

3 Pre-exposure to food odors improves postprandial fat utilization

Following premeal food odor stimulation, postprandial fat utilization was found to be enhanced in a manner linked to leptin receptors, independent of orexin in the brain Inhibitory and dopaminergic reward pathways, increased serum triglycerides and cholesterol in chylomicron and very low-density lipoprotein fractions, and promoted tissue-specific regulation of metabolic activity during refeeding, significantly increased metabolism in the liver flow. In addition, a mechanistic study of sympathetic modulation during refeeding found that prestimulation of NCD odor reduced HSL phosphorylation in eWAT and Ucp1 and Pgc1a expression in brown adipose tissue after refeeding.

4 Beneficial effects of food odor stimulation in obesity

Intermittent fasting (twice a week for 24 hours) in mice fed a high-fat diet (HFD) revealed no additional effect of HFD odor stimulation on body weight and food intake effect, but lowered blood sugar levels. Moreover, HFD odor stimulation resulted in decreased levels of insulin resistance index HOMA-ir and insulin secretion index HOMA-β. In the oral glucose tolerance test, peak glucose levels were reduced in the HFD odor-stimulated group. Thus, chronic food odor stimulation augments the benefits of intermittent fasting on glucose metabolism without additional weight changes in diet-induced obesity.

Figure 3. Effect of food odor stimulation on metabolic function of diet-induced obese mice . (Image source: Nature Metabolism)

Epidemiological evidence suggests that individuals with obesity, insulin resistance, or type 2 diabetes have olfactory dysfunction, however there is also opposing evidence that obese individuals are more sensitive to tasty and energy-dense food odors. Although these studies are still contradictory, olfactory sensitivity is a key factor in maintaining metabolic health. There have also been previous reports on the dynamic regulation between olfactory neurons and fat storage. Different odors trigger different olfactory neurons, which in turn affects Fat metabolism process.

In general Smelling food during fasting can double regulate lipid metabolism, enhance lipid mobilization in the body during the fasting period, and promote lipid utilization and control blood sugar levels during the feeding period. This regulation helps maintain metabolic health in different environments in the body.

So struggling to lose weight Friends on the road, if you think about it this way, the goal of fat loss through food odor stimulation is just around the corner, but before this idea becomes a reality, diet control + exercise is the healthy way to lose weight!