Calories In
Hormonal Control of Hunger, Appetite, Energy, and Mood
How Does Your Body Regulate Hunger?
One of the key ways that your body regulates hunger is through the action of two hormones: leptin and ghrelin. Much like insulin and glucagon, these hormones act in opposing ways (Widmaier, 2019).
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As insulin activity causes your body to store more fat, the increase in the number of fall cells triggers the release of leptin. Leptin then acts on the hypothalamus and reduces the hunger signals that it sends out. In contrast, ghrelin is released from the small intestine when your body uses its energy stores through the action of glucagon. Ghrelin's function serves to increase hunger and facilitate fat storage (LibreTexts, 2019).
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These hormones work to prevent your body from deviating from a certain level of body fat storage, but they're not the only factors at work in determining your hunger. Additionally, you calorie intake will also be influenced by your appetite, the desire to eat, which is the desire to eat based on psychological and physiological phenomena in the body (Widmaier, 2019).
Other Factors That Influence Your Hunger and Appetite
Theoretically, leptin and ghrelin should allow your body to signal hunger levels that promote consistent weight maintenance. So why do some many people find it so hard to reach and/or maintain a healthy weight?
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This is because there are a number of other factors that influence hunger and appetite, as well as physiological conditions that can override and undermine the normal calorie intake control systems at work.
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According to research into satiety (the sensation of a fulfilled or satisfied appetite), the types of foods that we eat can be manipulated to generate more or less hunger. Certain foods, especially those with higher fiber and/or protein content, can help reduce or control excessive appetite and minimize over-eating (Chambers, McCrickered, & Yeomans, 2008).
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Additionally, scientists have found that many of the hyper-palatable, processed foods we eat trigger the reward systems in our brains, which are largely controlled by the release of dopamine. Foods engineered to trigger a physiological pleasure reaction, which often have high levels of simple sugars and fat, can create a conditioned response that ingrain cravings and over-eating (Cassidy & Tong, 2017).
The effects of eating these foods can undermine weight loss efforts because, by triggering and manipulating reward systems in the body, they override the natural hunger controls acting through the hypothalamus that normally would inhibit increased calorie intake by triggering patterns of over-eating reinforced through food cravings (Amin & Mercer, 2016).
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Interestingly, researchers have learned that changing the amount of craved foods eaten doesn’t change craving frequency, so typically restrictive diets can often fall into the trap of triggering hard-to-ignore cravings. Instead, changing the frequency of eating these foods, rather than the amount eaten, has been shown to reduce how often the conditioned cravings that they trigger occur (Apolzan et al., 2017).
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“Satiety is moderated [by] a combination of cognitive, sensory, and physiological signals” (Chambers, McCrickered, & Yeomans, 2008).
