Episode 169: Hungry for Knowledge: The Role of Leptin and Ghrelin in Weight Management

[00:00:00] Welcome back to the Back on Track Achieving Healthy Weight Loss, where I help you get on track and stay on track with your weight loss journey. I'm your host, Dr. Alicia Shelly. So let's get started.

[00:00:27] Welcome to the Back on Track Achieving Healthy Weight Loss podcast. I'm your host, Dr. Alicia Shelly. Did you know that two tiny hormones could be controlling your hunger and weight gain?

[00:00:39] Today, we're going to be talking about the hormones leptin and ghrelin and how they regulate hunger, the sensation of feeling full, and your weight.

[00:00:50] Now, what are leptin and ghrelin? First, let's talk about leptin. So leptin is called the satiety hormone or the hormone that makes you feel full.

[00:01:01] It's produced by fat cells and signals the brain when you are full. It is primarily produced by fat cells and plays a crucial role in regulating your body weight by controlling hunger and energy balance.

[00:01:15] It's often referred to as a satiety or starvation hormone because of its function and signaling the brain that the body has enough energy stored in fat cells and doesn't need more food.

[00:01:28] It regulates appetite. And the reason is, or some key functions of leptin is that not only number one, it regulates appetite.

[00:01:37] Leptin communicates with the hypothalamus, which is the part of the brain that controls hunger and eating behavior.

[00:01:43] And when fat stores increase, leptin levels rise and signals to the brain to reduce appetite and food intake.

[00:01:50] Another key function of leptin is the energy expenditure, meaning that in addition to reducing hunger, leptin also regulates how much energy the body burns.

[00:02:02] Higher leptin levels boost energy expenditure, while lower levels signals the body to conserve energy, especially during periods of starvation or weight loss.

[00:02:13] Also, leptin can prevent overeating.

[00:02:17] So leptin's job is to prevent overeating by making you feel full and satisfied after a meal.

[00:02:23] Now, besides leptin being released by fat cells, it can also be released continuously due to various factors.

[00:02:32] For example, number one, after eating, leptin levels increase, signaling the brain that you're full and that you should stop eating.

[00:02:40] This is especially true after meals that are high in calories or carbohydrates.

[00:02:45] Remember Thanksgiving dinner?

[00:02:47] After eating, you're like, oh, let me sit down here and take a nap.

[00:02:51] Because sometimes it can be a lot of calories and other times it can be a lot of calm.

[00:02:55] So it definitely can make you feel stuffed.

[00:02:58] Also, so your circadian rhythm can affect your leptin levels.

[00:03:02] So leptin levels naturally fluctuate throughout the day.

[00:03:05] And they are generally higher at night, which may help regulate appetite and reduce hunger during sleep.

[00:03:12] Also, in response to overheating, that can play a role as well.

[00:03:16] So when a person eats more calories than their body needs, overeating or overfeeding,

[00:03:21] leptin levels rise to signal the brain to reduce appetite and increase energy expenditure or burning of those calories.

[00:03:30] Also, the more body fat you have, the more leptin is produced.

[00:03:34] So leptin levels rise as fat stores increase and fall when fat stores decrease.

[00:03:41] Essentially, it reflects the amount of energy stored in fat cells.

[00:03:45] However, during periods of fasting or calorie restriction, leptin levels usually decrease,

[00:03:51] signaling to the brain that the body needs more energy and increasing your hunger.

[00:03:56] Now, there is a condition called leptin resistance.

[00:03:59] And some individuals, particularly those who are overweight or living with obesity,

[00:04:06] the brain may stop responding properly to leptin.

[00:04:10] This condition is known as leptin resistance.

[00:04:13] So despite having high levels of leptin, the brain does not receive that signal to stop eating,

[00:04:18] leading to increased hunger and overeating, which contributes to weight gain.

[00:04:23] Leptin resistance can also reduce energy expenditure, making it harder to lose weight.

[00:04:29] That can be very uncomfortable, especially if you're living with obesity,

[00:04:33] because your leptin levels aren't working well.

[00:04:36] And there's not a way that we can be able to check leptin in the regular doctor's office.

[00:04:42] Usually they've been doing research looking around leptin to see how we can improve this

[00:04:47] and help people with their weight.

[00:04:49] Now let's move on to our next hormone, which is the ghrelin hormone.

[00:04:54] Now, the ghrelin hormone is often referred to as the hunger hormone.

[00:04:59] It's primarily produced in the stomach and it plays a critical role in regulating appetite and energy balance.

[00:05:06] Some of its key functions is that number one, it stimulates appetite.

[00:05:10] Ghrelin is released into the bloodstream when the stomach is empty

[00:05:13] and signals the brain to increase appetite and stimulate the desire to eat.

[00:05:19] And usually levels of ghrelin typically rise before meals and fall after eating,

[00:05:24] which aligns with that feeling of hunger and satiety.

[00:05:27] It also can promote food intake.

[00:05:29] So it encourages food consumption by enhancing the food appeal.

[00:05:34] So when you're hungry, all of a sudden this plate of cookies looks so good.

[00:05:39] You have to have it right now.

[00:05:41] So it improves that food appeal and influences food preferences,

[00:05:45] where you'll just eat what's available versus what may be healthy.

[00:05:49] Also, it can regulate energy balance.

[00:05:52] It plays a role in energy balance by promoting fat storage and influencing metabolism.

[00:05:57] It can encourage the body to conserve energy during periods of calorie restriction or fasting.

[00:06:03] Also, it works to stimulate the secretion of the growth hormone from the pituitary gland,

[00:06:08] and it plays a role in growth and metabolism.

[00:06:12] Now, usually, like I mentioned, ghrelin is released.

[00:06:15] The levels rise significantly before meals, and it drops after eating.

[00:06:20] But sleep and the circadian rhythm also can play a role with ghrelin levels.

[00:06:26] Ghrelin levels can also be affected by your sleep patterns,

[00:06:29] and a lack of sleep has been associated with increased ghrelin levels and increased hunger.

[00:06:34] Some other factors that influence the ghrelin levels is your body weight.

[00:06:38] Obesity is often associated with higher levels of ghrelin,

[00:06:41] but the body's sensitivity to ghrelin may change,

[00:06:45] leading to increased hunger despite already having high ghrelin levels.

[00:06:51] Also, certain diets play a role.

[00:06:53] So diets that are high in carbohydrates or high in fat

[00:06:56] may have a different impact on ghrelin levels compared to more balanced meals.

[00:07:01] It can increase it.

[00:07:02] Also, chronic stress can lead to dysregulation of ghrelin levels,

[00:07:07] which increases appetite and cravings for unhealthy foods.

[00:07:11] Like, have you ever been super stressed out and just want to eat all the things,

[00:07:16] like cookies and cakes and all that kind of stuff?

[00:07:19] That's why.

[00:07:20] Because of the fact of the dysregulation of the ghrelin levels.

[00:07:23] Also, certain hormones can interact with ghrelin,

[00:07:27] such as leptin, insulin, peptide YY,

[00:07:31] which can help regulate appetite and energy balance.

[00:07:34] And when individuals lose weight or restrict their calories,

[00:07:38] ghrelin levels can increase,

[00:07:40] which may lead to increased hunger and a desire to regain the lost weight.

[00:07:45] And so I always tell my patients about that set point theory

[00:07:48] where your body has a certain weight it wants to be.

[00:07:51] So when you lose weight, your body's kind of working against you to get back to that

[00:07:56] safe weight or set point weight.

[00:07:59] So that's how the body uses the ghrelin to make you feel more hungry.

[00:08:03] Also, there've been some studies that suggest that people with obesity

[00:08:06] may have elevated ghrelin levels,

[00:08:09] which contribute to difficulties with achieving and maintaining the weight loss.

[00:08:13] Now, I just want to make sure you all,

[00:08:16] just in summary,

[00:08:18] the leptin and ghrelin,

[00:08:19] sleep can play a role in that leptin and ghrelin,

[00:08:23] as the lack of sleep can decrease your leptin levels

[00:08:26] and increase your ghrelin levels,

[00:08:27] leading to more hunger and potential weight gain.

[00:08:30] So it's important that we aim for at least seven to nine hours of sleep

[00:08:35] in order to keep our leptin and ghrelin balanced.

[00:08:38] It's important to create a sleep routine,

[00:08:40] avoid screens before bed,

[00:08:42] and keep a consistent bedtime to help.

[00:08:45] Also, chronic stress can affect both leptin and ghrelin hormones,

[00:08:49] which leads to increased appetite and cravings for high calorie foods.

[00:08:54] So it's important to make sure that you have your own stress management,

[00:08:58] management techniques,

[00:09:00] such as either mindfulness, yoga, deep breathing,

[00:09:03] prayer to kind of help reduce your stress-related disruptions,

[00:09:07] such as disruptions in the leptin and ghrelin.

[00:09:09] Also, the diet, how we eat can play a role.

[00:09:13] High fat and processed foods can impact the balance of leptin and ghrelin.

[00:09:17] So it's important to make sure you have more of a balanced diet,

[00:09:21] focusing on whole foods,

[00:09:23] and balanced meals to support hormone regulation.

[00:09:26] Certain nutrients can help, like omega-3, magnesium,

[00:09:30] which can help balance those hormones,

[00:09:32] and focusing on lean proteins, healthy fats,

[00:09:35] and fiber to stabilize your blood sugar and hormones.

[00:09:39] And then, of course, activity, physical activity.

[00:09:43] Exercise is so important.

[00:09:44] So having regular physical activity

[00:09:46] can help improve leptin sensitivity

[00:09:49] and help manage hunger.

[00:09:50] Making sure that you're incorporating

[00:09:52] at least 30 minutes of physical activity,

[00:09:54] including strength training two to three times per week,

[00:09:57] to kind of help with balancing out the hunger,

[00:09:59] the leptin and ghrelin hormones.

[00:10:01] So in conclusion,

[00:10:03] leptin and ghrelin play a huge role

[00:10:05] in our appetite regulation.

[00:10:06] And although we don't have therapies yet to regulate them,

[00:10:10] we can focus on things that we can change,

[00:10:12] such as making sure we get a good enough rest,

[00:10:15] exercising, eating a balanced diet,

[00:10:17] and managing our stress better.

[00:10:18] I thank you again for joining us

[00:10:20] on the Back on Track Achieving Healthy Weight Loss podcast.

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