Dr. Andrew Huberman, Ph.D. is a Professor of Neurobiology and Ophthalmology at Stanford University School of Medicine. His lab focuses on neural regeneration, neuroplasticity, and brain states such as stress, focus, fear, and optimal performance.
In this episode of Huberman Lab, Dr. Huberman breaks down how hormones from out gut, liver, pancreas and brain control our appetite, tools to adjust hormones and achieve weight loss goals, and areas of the brain that control our desire to eat and satiety.
Host: Andrew Huberman (@hubermanlab)
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
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
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
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
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