Clients often tell me they struggle to diet because they can’t get their hunger under control. But hunger is not an issue of being more disciplined or having more willpower. It’s a hormonal issue.
When we think of hormones we often think about oestrogen and testosterone and their role in puberty, libido, and the reproductive system. But, our bodies also produce hormones which regulate our appetite. In this article, I’m going to talk about one of them called ghrelin and tell you everything you need to know about it and how to keep it in check.
All About Ghrelin
Ghrelin controls hunger, food intake and combined with growth hormone, fat storage. Its main function is to increase appetite. It makes you consume more food, take in more calories and store fat.
This hormone is produced in your stomach and secreted when your stomach is empty. It sends signals to the hypothalamus, the part of your brain which governs your hormones and appetite, that it’s time to eat, by increasing your appetite. The lower your levels, the fuller you feel and the easier it is to eat fewer calories. After eating, ghrelin levels decrease because our stomachs are full and we’re satiated. They don’t rise again until the body starts looking for more energy. Ghrelin peaks every four hours or so–roughly corresponding to mealtimes.
So, if you want to lose weight, lowering your ghrelin levels can be beneficial. On the flip side, if you under-eat or struggle to gain weight, higher ghrelin levels may help you consume more food and calories.
Ghrelin may sound like a terrible, diet-wrecking hormone. However, our hormones have specific jobs to do in the body. If we never felt hungry, would we take as much joy from the food we eat? How would we know when we’re low on nourishment? How would we function at our best? In the past ghrelin played an important role in survival by helping people maintain a healthy level of body fat.
While you might assume obese people have higher ghrelin levels, they may just be more sensitive to its effects. Research shows their ghrelin levels are actually lower than in lean people, and are also associated with imbalances in other appetite controlling hormones. This suggests that over time, overeating can decrease sensitivity to the hormone, meaning we lose this essential control mechanism. Studies have also shown that after obese people eat a meal, ghrelin only decreases slightly. Because of this, the hypothalamus doesn’t receive as strong of a signal to stop eating, which can lead to overeating and weight gain.
If you’re trying to lose weight, you might be wondering how you can keep your ghrelin levels low. It doesn’t mean jumping to calorie restriction and starvation as this will increase your ghrelin levels, potentially lead to overeating and storage of fat.
Interestingly, research shows that intermittent fasting can significantly decrease ghrelin, increase the feeling of fullness, and decrease the desire to eat. This has certainly been my experience with the manageable type of intermittent fasting I do with my clients.
I’ve highlighted a few tips here to help keep this specific hormone in check:
Eat a diet rich in fibre from fruit and vegetables, legumes and wholegrains. A high fibre intake slows the stomach’s emptying rate, keeping you full for longer, and also stretches the stomach which sends fullness signals to the brain. Foods high in fibre also tend to be lower in calories and higher in nutrient density.
Eat your calories rather than drinking them. Solid calories and liquid ones can affect appetite differently. Solids provide a greater sensation of fullness than liquids. This may in part be because the extra chewing time allows solids to stay in contact with the taste buds for longer, which can promote feelings of fullness. Solids also require longer digestion which keeps you feeling full for longer.
Indulge in some dark chocolate.The bitterness of dark chocolate is thought to help decrease appetite and diminish cravings for sweets.Researchers also believe the stearic acid in dark chocolate can help slow digestion, further increasing feelings of fullness. Amazingly, one study observed that simply smelling 85% dark chocolate decreased both appetite and hunger hormones just as much as actually eating it!
Eat protein with every meal Incorporating a portion of lean or vegetable protein into each meal (eggs, oily fish, organic chicken or turkey, fermented tofu, beans and pulses) will slow gastric emptying, keeping you fuller for longer. One of the mechanisms behind this is a reduction in ghrelin levels.
Spice Up Your Meals. One small study found that consuming 2 grams of ginger powder diluted in hot water at breakfast reduced the hunger participants felt after the meal. Capsaicin, found in hot peppers, and capsiate, found in sweet peppers can help decrease hunger and increase feelings of fullness.
Manage stress. Studies in animals have shown that exposure to chronic stress increases circulating ghrelin (Massachusettes Institute of Technology, 2013). It also interacts with the brain’s reward pathways to increase food intake, including the consumption of sweet food over bland food. This creates a vicious cycle where we begin to see food as a comfort during times of stress and anxiety. Incorporate yoga, meditation or breathing into your daily routine, get out for a walk or run in nature, find something that works for you to allow you to live (and eat) more mindfully.
Sleep well. Sleep deprivation has been associated with an increase in ghrelin levels, appetite and hunger comparative to sleeping for longer periods. Research shows that individuals who sleep less than seven hours per night rate their fullness levels after breakfast as 26% lower. Aim for 7-9 hours per night, practice good sleep hygiene by limiting screen time, avoiding heavy meals and alcohol before bed, and try to stick to regular sleep and waking up times to regulate the circadian rhythm.
Exercise. This is an inconclusive area as far as research is concerned. Exercise reduces appetite for some people but not all. Often my female clients tell me they are hungrier after they exercise. Interestingly, a small-scale study of 20 women funded by the National Institutes of Health found that exercise only reduced appetite in lean women. Other research suggests women, but not men, respond to starting an exercise regimen with changes in hormones that lead to appetite stimulation, but it isn’t known if the differences continue over the long term. In terms of types of exercise, some research suggests that aerobic activities such as running suppress appetite more than lifting weights or other forms of resistance training.
My advice is that until we know more of the nuances underlying exercise and appetite control, be mindful of how you feel after exercise. If it does increase your hunger, make sure you have something healthy to eat straight afterwards so you aren’t tempted to binge on unhealthy high carb foods.
If you’re looking for support with weight loss or indeed weight gain, incorporating these diet and lifestyle changes would be a great place to start. It’s important to remember however, that ghrelin is only one of many interrelated factors which could be impacting on your health and well-being. That’s why I create bespoke plans specific to my clients’ personal health and fitness goals.