The Science behind Food Cravings and how to manage them

September 29 08:36 2023 by admin-blog-kh Print This Article

Summary

Food Craving is a physical condition that has both physical, and psychological or behavioural aspects, to it. Food Craving once in a while, or to a small extent, is not a problem, it can be easily manageable and reversed. However, if it is not addressed, it can lead to food addictions over time, the nature of which is similar to drug and alcohol addiction. In such a case, there are serious complications such as obesity, diabetes, heart disease, liver disease and certain cancers too. In this article, we will learn how to manage these cravings.

The physiology of True Hunger versus Food Craving

What is True Hunger and how does it work?

A few hours after we have had a meal and the food is being digested, a hormone called Motilin triggers what is called ‘Migrating Motor Complex’ (MMC). This is a period of intense electromechanical activity in the smooth muscles of the GI tract. This occurs in phases. Towards the end of the activity, undigested food is swept up and pushed through the digestive tube for storage and elimination later. Then a series of small contractions happen in these muscles. That is the rumbling sensation that happens in the stomach when we feel hungry. A hormone called ghrelin is also released in the stomach. These are signals to the person that he/she must consume energy-rich food now. The hunger mechanism or circuitry happens out of the hypothalamus which lies at the base of the brain.

Once the person responds to the hunger signals and starts consuming a meal, appetite hormones such as glucagon-like-peptide and cholecystokinin are released from the digestive tract, while hormone leptin is released from the fat cells. All these cause feelings of fullness and sends a signal to brain, which in turn tells the person to stop eating.

The above cycle goes on smoothly as long as the person is consuming a healthy diet which is not too heavy on sugar, salt or fat, the person is not stressed out, and he/she has had adequate sleep. However, if these conditions are not met, the digestion cycle goes haywire and the secretion of hormones gets disturbed.

What is Food Craving and how does it work?

Hyperpalatable foods are a class of foods that are quick and easy to digest because they are heavy in starch or refined carbohydrates. They are also rich in salt and fat. Typical examples would be potato chips, French fries, packaged snacks and condiments made of maida, bakery items, sweets and sweetened beverages like soda and fruit juices, and high-fat items like ice-cream and milk-chocolate. All these are quick to digest so they cause rapid spikes in insulin and blood-sugar. Further, they are considered ‘tasty’ by the person and he/she would like to consume them again.

When we consume Hyperpalatable foods or those that are rich in fat, sugar and salt (what we call unhealthy food), over and again, the digestive cycle described in the previous section gets disturbed. It triggers the release of metabolic hormones like insulin, stress hormones like cortisol and dopamine, and appetite hormones like leptin and ghrelin. These cause the ‘reward centre’ in the brain to get activated. This is an area deep inside the brain and includes regions such as the hippocampus, insula and caudate. This is the area or mechanism that is responsible for our understanding of risk (or activity to be performed) and the reward that can be expected out of it. This governs all domains of our life and just not food alone. Once the area gets lighted up (after consuming Hyperpalatable foods), this memory is stored in the brain.

As a result of the memory, the person tends to crave or desire that particular food or similar foods once again. And each time he/she indulges the craving by consuming that exact food (and not regular, healthy food), the memory gets enhanced. In times of physical or emotional stress, or when the person has not had adequate sleep, the same cravings get activated, and the person reaches out to such food as against regular, healthy food. That is why, they are called ‘comfort food’ (as they give a false sense of comfort) and lead to bouts of binge-eating.

If these cycles are not broken (by adopting a healthy lifestyle), the person can get addicted to such foods. That is, even after consuming a meal and is actually full, he/she craves for that kind of food. And even while consuming that food, the feeling of fullness does not happen quickly, so he/she tends to consume more of that food, thereby creating a vicious cycle of weight-gain, stress, more craving and more indulgence.

Risk Factors for Food Craving

• Stress: As mentioned before, when the person is physically or emotionally stressed, the stress hormone cortisol is released. Thanks to the memory reinforced in the past, he/she automatically reaches out to, or prefers hyperpalatable foods, which sets up a psychological connection between stress and unhealthy food.
• Inadequate sleep: Not sleeping 7 hours or more per day can cause various changes in the body, and disturbs hormonal activity. Levels of leptin and ghrelin which regulate appetite and satiation get disturbed This leads to weight-gain, food craving and stress induced by lack of sleep, thereby sustaining the vicious cycle of food craving.
• Gender: Women in the menstruating age (pre-menopausal) are more prone to food cravings than men and find it more difficult to resist unhealthy foods. This is because hormonal changes that happen throughout the cycle, and month after month, cause stretches of high food craving. During periods, estrogen levels are low and progesterone levels are high. The brain has receptors for estrogen, and a reasonably high level of estrogen is associated with feeling satiated after eating. Low levels prevent this, making the person experience cravings. Estrogen also suppresses hunger by reducing levels of the ghrelin hormone and increasing the working of cholecystokinin, which suppresses appetite. Low estrogen levels reverse this function, leading to bouts of craving.
• Exercise: Sessions of moderate to heavy exercise are known to reduce the levels of hormone ghrelin which stimulates appetite, and increases the levels of hormones – leptin and glucagon-like-peptide (GLP) which suppresses appetite, for a short duration after exercise. This implies that people who exercise regularly or live an active life are less prone to such food-cravings. In contrast, people with a sedentary lifestyle are at higher risk of food-cravings.
• Medications: Certain anti-depressant and anti-psychotic drugs can create food cravings by interfering with the production of serotonin. Prednisone, a steroid-based drug can create leptin-resistance, so one is constantly feeling hungry and craving food.
• Behaviour: Seemingly harmless behaviour can sometimes increase the risk of cravings. For example, a bakery or eatery on the route back from work to home can make the person stop and indulge once in a while. This soon reinforces a behaviour where every time, he/she passes the eatery, he/she is tempted to stop by and indulge. Similarly, purchasing vegetables and fruits from a large supermarket where packaged snacks are available in the same aisle can influence the person to purchase them as well.
• Lifestyle: People who like to munch on a snack during or after smoking a cigarette reinforce a behavioural pattern because of which they begin to crave for both – a cigarette and the snack. Similarly, people who consume unhealthy snacks during a drinking session reinforce cravings for both a drink and the snack. People who consume a sweetened drink or a light snack immediately after exercising, begin to enjoy both over time, which creates such cravings. The benefits of exercise are totally lost, in such cases.
• Food Marketing: One of the biggest risk-factor that people tend to ignore is – Food Marketing! Considering that the demand for unhealthy, packaged, snacks and condiments are so high, food and beverage manufacturers invest thousands of crores of rupees in their advertising. From ads on TV, internet, magazines and newspapers to hoardings and bill-boards in all commercial neighbourhoods, food advertising is everywhere! Children and young adults who have not yet formed the discipline of a healthy lifestyle are easily influenced by such marketing. In the process, a culture of consuming unhealthy foods starts at a young age. During adulthood, this leads to repeated cycles of food craving, binge eating and long-term food addiction.

How to manage Food Cravings?

Our earlier article – ‘8 effective ways to manage food craving’ – has covered this in detail. So, we will only give some brief pointers here.

• Eat a balanced and nutritious meal rich in protein and fibre which are satiating.
• Avoid long stretches of not eating by consuming a small and nutritious meal every 3-4 hours during your waking hours.
• Avoid hyperpalatable or ultra-processed snacks rich in salt, sugar, fat, refined carbohydrates and low in in nutrition, as much as possible.
• Replace unhealthy snacks with whole fresh fruits, nuts and unsweetened yogurt.
• Avoid food pornography. That is, avoid online sites and posts that glorify unhealthy food; avoid TV shows that showcase a wide variety of foods.
• Change your behaviours: Avoid those candies in the office pantry, avoid that eatery on the way back home, avoid purchasing condiments along with fruits and vegetables, etc.
• Practice mindfulness when you feel a craving. Question yourself why you are feeling the craving. Distract yourself, or indulge in a healthy snack. Practise mindful eating.
• If you enjoy the ‘high’ from unhealthy foods, replace with activities such as walking, running, jogging, swimming, watching educational videos, singing, dancing, etc.

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