Leptin is the satiety hormone. Just like ghrelin is released when you’re hungry and your stomach is empty, leptin is released when you’re full and satiated. Interestingly, as opposed to ghrelin, leptin is positively correlated with body weight, meaning those with more body fat/body weight produce more leptin.
How does leptin affect obese individuals? Obese individuals have screwed up signals of satiety and hunger. We have a whole article that discusses the effects of ghrelin-leptin balance on obesity. But to put it simply, obese people are leptin-resistant.
How does leptin affect normal individuals? At the end of every meal, your stomach distends with freshly eaten food that signifies fullness. With more food you intake, your body fat rises, causing your leptin levels to rise along with your weight. Understandably so, your tendency to eat declines as your satiety levels are higher and you burn more.
Is more leptin good then? Well, you could think that if you have more leptin, you will stop having the urge to eat and weight loss would then become easy but it’s not that simple. On one hand, as you get obese, you get leptin resistant, meaning although your leptin levels are high, your body is insensitive to its presence, so your brain doesn’t sense these fullness signals and you just don’t know when to stop eating. On the other hand, as you lose weight by calorie restriction and dieting, your leptin levels decline and ghrelin levels go up, causing you to feel less satiated and hungrier over time. So while more leptin is certainly good, that doesn’t mean you have to maintain a higher body weight in order to elicit more leptin in your body. By doing so, you’ll only run the risk of hitting leptin resistance.
What’s the solution? The solution is then to eat just enough and the right amount of foods that are not only nutrient-dense but also rich in fiber and protein to ensure satiety signals are released after each meal and leptin levels are reasonably stable. In addition, losing body weight in a controlled manner through a calorie deficit of no more than 400 kcal daily, and incorporating a balanced diet with all the essential macro- and micronutrients are some ways to fine-tune the delicate balance between ghrelin and leptin.
For more info on understanding ghrelin-leptin balance and beating leptin resistance, do check out our article here.
We spoke about insulin resistance here. Leptin resistance has strikingly similar effects. One article (1) has recently identified leptin as a marker of insulin resistance in type 2 diabetes. Leptin and insulin are linked by common signaling pathways. Studies have found that overeating causes both leptin and insulin resistance in a manner that renders the hypothalamus insensitive to the presence of both hormones (2) (Leptin reverses insulin resistance and diabetes mellitus in mice with congenital lipodystrophy). It is suggested that leptin drives hypothalamic insulin resistance in obese individuals.
How to know if you’re leptin resistant?
- Well, first of all, think about your eating habits. Do you eat a lot of processed and packaged foods? Are you frequently consuming foods containing fructose corn syrup and starch? (3) Do you feel dizzy in-between meals if you don’t snack? Would you rather prefer a pre-packaged orange fruit juice as opposed to a fruit?
- Now, take a look at yourself in the mirror. Do you carry most of your weight around the mid-section? If you’re an overweight male, the tendency to carry more visceral fat is higher; as such your insulin and leptin levels would be understandably on the higher side. In women, however, leptin levels were higher with more subcutaneous fat, i.e. fat beneath the skin (4). .
Leptin resistance in a nutshell
Overeating/ Bad food habits Weight gain More fat cells More leptin production Leptin resistance Brain can’t sense fullness in the stomach You are driven to eat more Weight gain
Having beyond the normal level of body fat may produce leptin but as a twisted side-effect, induce insensitivity to leptin, making you hungrier and causing your appetite to go out of whack.
Diet choices to reduce/reverse leptin resistance:
- Load up on green, leafy vegetables in their raw or steamed form. This will lower the level of bad cholesterol and reverse the programming of your fat cells to produce leptin.
- Make sure every meal you have has 40 percent protein and 30 percent fats. Protein-dense grains such as quinoa and oats are a good choice. Healthy fats like avocadoes, olive oil should be taken in some form.
- Adding a teaspoon of cold-pressed coconut oil to your morning coffee is an easy way to sneak healthy fats into your diet.
- Replace sugary treats with berries; fruit juices with detox drinks and calming herbal teas. If possible, have green tea or black coffee in-between meals instead of reaching out for snacks.
- Try meal-pairing. Have fruits like bananas and apples with nut butter for a generous dose of healthy fats and proteins that will induce satiety, keeping you full for a long time.
- Have a meal rich in protein for dinner. If you’re a vegan, cottage cheese and tofu can do the trick for you, and if you consume animal meals, choose turkey, salmon, fish, or chicken.
- Have healthy carbs like whole-wheat cereals, legumes, and lentils. Black bean soup, quinoa porridge, and humus are good options. Also, include probiotic/fiber-rich foods in your breakfast to boost gut health.
Recommended daily practices
- Never resort to crash dieting. As discussed earlier, your brain will be confused into thinking you’re in starvation mode and spike up ghrelin levels as a counter-measure to the reduced leptin secretion, leading you to eat more and crave more.
- Always choose good carbs over bad. The leptin diet recommends 30% carbs with every meal, and this portion should come from healthy food sources in their whole, unpolished form.
- Avoid fruit juices and items containing fructose corn syrup. They contain high amounts of fructose that are bad for your liver and manipulate the leptin signaling networks of your system.
- Avoid artificial sweeteners, soy products, diet soda, and other energy drinks. Consider having homemade detox drinks instead.
- Exercise portion control with each meal, i.e. no more than 500 kcal with each meal and make sure not to create too much of a daily calorie deficit (~500kcal per day) to ensure weight loss in a controlled manner (1.5-2.5 kgs/month).
- Include moderate exercise (75 minutes cardio per week), along with strength training in the form of squats, planks, and push-ups to help with insulin and leptin resistance.
- Take fiber supplements and drink lots of water. Most importantly, sleep well. Sleep maintains ghrelin and leptin homeostasis, allowing your brain to better understand when you’re hungry/full.