How Hormones Control Hunger, Eating & Satiety

Key Takeaways

• Hormones are involved in both the desire to eat and satiety or reduction in appetite

• Emulsifiers in highly processed foods limit the gut’s ability to identify what is in the food and send satiety signal to shut down hunger

• Neurons in the gut that sense sugar trigger the release of dopamine and encourage you to eat more sugar

• The order you consume macronutrients influences blood glucose levels: carbs and fat early in meal give rise to blood glucose; eating fibrous vegetable first will blunt glucose increase

• If you struggle with blood glucose regulation: move or exercise before or directly after eating, be mindful of the order in which you consume foods

• Managing blood glucose plays a critical role in managing cholesterol as well

• Over the counter supplements that have been shown to decrease blood glucose: berberine, ginseng, magnesium, apple cider vinegar and acidic foods, yerba mate, chromium

Biology & Physiology Of Appetite

• Hypothalamus is a control station for hunger, eating, and satiety – involved in promoting both feeding and not eating

• Arcuate nucleus: a set of neurons in the hypothalamus

• Melanocyte stimulating hormone (MSH) is released from the pituitary gland and reduces appetite

• Activated by ultraviolet light to eyes and keeps appetite in check

• MSH is the reason animals and humans tend to have reduced appetite in the warmer months

• Agouti-related peptide (AGRP) neurons stimulate eating and emotion involved in anticipation of food – if stimulated, you will eat like crazy

• Ghrelin is released from the GI tract and increases the desire to eat by stimulating neurons that increase hunger and anticipatory signals

• Ghrelin causes cravings or desires to eat certain foods at certain times of day

• If you generally eat at the same time daily and begin feeling hungry at those times – it’s ghrelin activating that sensation of hunger

• If you want to change the eating window (e.g., longer fasting) ghrelin secretion can be shifted by 45 minutes per day – so ease into it and push back the window every day until it’s where you want to be

• Cholecystokinin (CCK) released by the gut has a powerful effect in reducing appetite

• CCK release is governed by neurons and mucosa of the gut microbiome and stimulated by fatty acids (specifically omega-3s), amino acids (specifically glutamine*), and sugar

• Glutamine can reduce sugar cravings – but also increase blood sugar levels

• *Many cancers and tumors feed on glutamine so always talk to a doctor before supplementing

• Insular cortex gets input from the mouth has and powerful control in whether you enjoy what you’re eating, the sensation of eating, whether you want to continue eating, etc.

• Endocrine signals are involved in hunger and desire to eat

Damaging Effects Of Processed Foods

• A calorie is not a calorie

• Emulsifiers in highly processed foods shut down CCK and turn off recognition of satiety

• Emulsifiers in highly processed foods limit the gut’s ability to identify what is in the food and send satiety signal to shut down hunger

• Neurons in the gut that sense sugar trigger the release of dopamine and encourage you to eat more sugar

• Highly processed foods increase weight gain, disrupt lining of gut, and disrupt hormonal and neural systems that increase desire to eat

• Increased consumption of highly processed foods has caused staggering increases in diabetes, obesity, and other related diseases

Insulin

• Food is broken down into sugar and released as energy

• Blood sugar needs to be kept in a certain range

• If glucose gets too high, neurons can be damaged or killed causing loss of sensation in hands, feet, and eyes

• Type 2 diabetes: insulin is secreted from the pancreas but the person is insulin-insensitive – often associated with overweight and obesity

• Type 1 diabetes and often be managed by diet and lifestyle

• Type 1 diabetes: pancreas produces little or no insulin – often associated with weight loss

• Macronutrients are associated with an increase in blood glucose in the following order (highest to lowest): carbohydrates, fat, protein

• Glucagon: secreted when hungry

• The insulin system manages glucose, glucagon system pulls energy out of the liver and muscles for fuel until glycogen stores are depleted (then glucagon pulls from fat)

• The order you consume macronutrients influences blood glucose levels: carbs and fat early in meal give rise to blood glucose; eating fibrous vegetable first will blunt glucose increase

• Blood glucose levels can be heavily modulated by moving and exercise before eating

• Zone 2 cardio that lasts 30-60 min dramatically increases insulin sensitivity and stabilizes blood sugar

• High-intensity interval training and weight training repackage glycogen and trigger mechanisms to shuttle glucose to glycogen and storage of food

Breakdown Of Cholesterol

• Want LDL to be low and HDL to be high

• Fats don’t like water but you need to move fats in the bloodstream so HDL and LDL allow them to move through the bloodstream

• Adequate HDL is good because you can move fats to tissues that manufacture hormones

• When LDL is high, you can get a buildup of fat

• There’s a lot of debate about how dietary cholesterol impacts LDL and HDL

• How to keep LDL/HDL in the proper ratio: manage glucose

Supplements And Prescription Drugs

• Metformin reduces blood glucose by changing mitochondrial action in the liver

• Berberine is over the counter and mimics metformin with a similar pathway and results

• Chromium, ginseng, magnesium, apple cider vinegar, and acidic foods have been shown to have a minor impact on blood glucose

• Caffeine has been shown to slightly increase blood glucose

• Stevia is the best in terms of sweeteners and will not raise blood glucose like other artificial sweeteners – but the sweet taste itself will increase the desire to eat so will probably cancel out

• Yerba Mate can help regulate blood sugar and has a slight appetite suppressant quality

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