A Hormonal Master Switch’s Connection to Weight Gain (POMC)

Exercise

Exercise may activate POMC neurons in the hypothalamus, especially those with leptin receptors. These leptin receptor-expressing POMC neurons are vital for appetite control [R].

High-intensity exercise is probably the best strategy to lose weight. In addition to promoting fat burning, the increased norepinephrine production may suppress food intake according to a study in rats [R].

Being active burns calories and jump-starts metabolism. Some studies suggest it also increases BDNF, which supports mental health and might cause us to eat less [R].

Exercise also increases endorphins, which activates mu-opioid receptors and also suppresses appetite [R].

Aerobic exercise (like walking, running, swimming, etc) has also been shown to cause major reductions in belly fat in multiple studies [R, R].

Exercise activates POMC neurons in the hypothalamus, which may help explain why exercise can reduce appetite.

Moderate Sun Exposure

Some POMC neurons in the hypothalamus appear to express vitamin D receptors, suggesting that vitamin D may activate them. Some studies have suggested that vitamin D and ultraviolet (UV) light, both available through sun exposure, may directly stimulate POMC [R, R, R].

Vitamin D deficiency is suspected to contribute to obesity in some cases, though more research is needed [R].

UV is hypothesized to prevent obesity in animals, whether or not they are deficient in vitamin D [R].

In one study, intense light exposure, particularly in the morning, was associated with a lower BMI independent of sleep duration and timing [R].

Specifically, having a majority of the average daily light exposure above 500 lux earlier in the day was associated with a lower BMI [R].

Exposure to at least 45 minutes of morning light (between 6-9 am at 1,300 lux) for 3 weeks in obese women resulted in reduced body fat and appetite. Although encouraging, more research is needed to verify the link between sunlight exposure and weight loss [R].

Vitamin D and UV light (both available through sun exposure) may directly activate POMC neurons.

Positive Social Interaction

Oxytocin neurons and POMC neurons appear to be in close communication; when oxytocin neurons fire, they may stimulate POMC neurons [R].

Oxytocin is released by positive human interactions and has been shown to decrease hunger in multiple animal studies [R].

Love also increases NGF, which reduces appetite, and increases endorphins, which activate mu-opioid receptors [R].

Fish & Seafood

DHA, a prominent omega-3 fatty acid found mostly in fish and seafood, may increase POMC production [R].

Fish is also hypothesized to reduce leptin; higher leptin is associated with obesity. In young, overweight men, the inclusion of either lean or fatty fish or fish oil as part of an energy-restricted diet resulted in approximately 1 kg more weight loss after 4 weeks compared to a similar diet without seafood or a supplement [R, R].

Spicy Foods

Capsaicin is believed to reduce appetite; one mechanism by which this may happen is the direct simulation of POMC neurons [R].

When capsaicin activates receptors (TRPV1), it may also speed up the metabolism and increase energy expenditure [R, R, R, R].

When ingested orally with green tea, capsaicin reduced appetite and food intake in humans. Early research indicates that taking capsaicin as a weight loss supplement is safe, but more must be known about its effectiveness [R, R, R].

If you like spicy food, you’re in luck: capsaicin is found in chili peppers and is responsible for their spicy flavor. The spicier the pepper, the more capsaicin it contains [R, R].

Resistant Starch

Butyrate is believed to induce the expression of the POMC gene [R].

Butyrate is a fatty acid produced by good bacteria in the gut when they digest resistant starch and fiber. The cells of the colon wall use this compound for energy [R].

Some evidence suggests that resistant starch may help promote weight loss in certain circumstances. However, the research on this topic has been broadly limited to animals.

In obesity-prone rats, dietary resistant starch and regular exercise prevented weight gain, apparently by reducing energy intake [R].

It reduces fat accumulation and blood glucose levels and increases the breakdown of fat through fermentation in the intestines, thus potentially improving weight control [R, R].

Resistant starch may stimulate fat burning by:

• Reducing fat accumulation and increasing fat oxidation after meals [R].
• Forcing the body to burn fat by lowering blood glucose [R].
• Decreasing fat production while increasing the production of phospholipids [R].

Butyrate, produced when gut bacteria digest resistant starch, may increase the expression of POMC.

Green Tea

A combination of EGCG and caffeine, both found in green tea, increased the expression of POMC in the hypothalamus in mice [R].

EGCG caused between 0.2 and 3.5 kg of weight loss in limited human studies. Green tea, meanwhile, is hypothesized to make us burn more calories, even at rest. In most studies, this amounts to a modest 3-4% increase in energy, though some studies have shown an increase as high as 8%. For a 2,000 calorie diet, 3-4% amounts to an additional 60-80 calories per day [R, R, R, R, R, R].

In one study of 60 obese individuals, the group taking green tea extract lost 7.3lbs and burned 183 more calories per day (on average) after 3 months [R, R].

Caffeine is a well-known metabolic booster. In 12 clinical trials on 135 people, caffeine (100-600 mg/day) increased energy use and fat burning. Paradoxically, the effects were more pronounced in lean than in overweight people. Caffeine also helped maintain weight loss in 2 long-term studies on 2,500 people [R, R, R, R, R, R, R, R, R, R, R].

Green tea contains both EGCG and caffeine, which in combination may increase POMC expression.

Probiotics

Because butyrate may increase the expression of POMC, butyrate-producing probiotics may be helpful for those with low-POMC variants [R].

Certain probiotics (L. gasseri, L. rhamnosus, and B. animalis) have been found to reduce intestinal inflammation, support gut health, and even promote weight loss [R, R].

L. gasseri significantly decreased BMI, abdominal visceral fat, waist and hip circumferences, and body fat mass in 210 healthy Japanese adults, with an 8.5% decline in abdominal fat area over twelve weeks. However, the authors warned that constant consumption of this probiotic may be required to maintain this effect [R].

In a clinical trial of 125 obese adults, L. rhamnosus induced weight loss, reduced fat mass, and reduced circulating leptin [R].

Additionally, L. rhamnosus CGMCC1.3724 improved liver parameters in a small trial of 20 obese children with liver dysfunction noncompliant with lifestyle interventions [R].

Probiotic bacteria that produce butyrate may increase POMC expression, helping to explain why some such strains are associated with weight loss.

Green Coffee Extract

Chlorogenic acid, the active compound in green coffee extract, has been found to increase POMC in mice [R].

In a clinical trial on 12 healthy volunteers, chlorogenic acid-enriched coffee increased weight loss by reducing sugar absorption. In another trial on 9 healthy volunteers, chlorogenic acids from coffee increased fat burning during sleep [R, R].

Both green coffee extract and a natural supplement with chlorogenic acid and several plant extracts reduced body weight and blood fat levels in 2 clinical trials on 121 people with metabolic syndrome [R, R].

Similarly, chlorogenic acid reduced body weight, body mass index, and waist circumference in another trial on 30 people with prediabetes (impaired glucose tolerance) [R].

However, dark roast (low in chlorogenic acid) coffee was more effective than light roast coffee at reducing body weight in a clinical trial on 30 healthy people [R].

The major active compound in green coffee extract increased POMC in mice and has produced promising results in human weight management trials.