Have you ever experienced a situation where, after not eating for a day, you surprisingly find yourself lacking the usual appetite? Perhaps you had to skip a meal at work, expecting hunger to strike later in the day, only to discover that your desire for food has diminished, and you could go even longer without eating. This intriguing phenomenon can leave you wondering about the underlying reasons behind this loss of appetite.
In this article, we will delve into the causes of not feeling hungry after not eating all day and explore the various factors that can contribute to this phenomenon such as stress, illness, medication, aging, or stomach disorders. These factors can affect your appetite and disrupt normal hunger signals in the body. There are multiple elements that can disrupt your usual hunger signals and dampen your appetite. We will also discuss the symptoms to watch out for when it comes to hunger and provide insights on how to navigate this situation effectively.
What Causes Loss of Appetite After Not Eating All Day?
Loss of appetite can occur after not eating for an extended period of time, even if you would typically feel famished. There are several reasons why you may experience a lack of appetite in such situations. Here are some common causes and related information to consider:
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Stress
Adrenaline serves several purposes in the human body. The one most know about is the “fight or flight” response. When you get stressed, your body reacts as if it’s in danger, which as a result, causes your brain to release chemicals, including adrenaline, which makes your heart beat faster and slow your digestion. This in turn can curb your appetite, but typically only lasts for a short period of time. If you’re stressed over a longer period of time, your body releases cortisol, which makes you hungrier, especially for high-calorie foods.
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Cold or Flu
When you aren’t feeling well, your immune system gets put into overdrive, releasing chemicals called cytokines that can make you feel tired and not hungry. Your body is telling you that you need to simply rest so that you can restore your energy levels to fight whatever is making you ill.
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Medication
There are many medications on the market today that contain the side effect of appetite loss. This is common when medications pass through a person’s stomach and digestive tract.
The most common medications and treatments often cause a low appetite:
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Antibiotics
- Muscle relaxants
- Drugs that treat anxiety
- Drugs that treat high blood pressure
- Sedatives
- Immunotherapy
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Hunger as Fatigue
An additional cause for a loss of appetite is that you actually are hungry, you just do not realize it. You most likely are not hungry in your stomach. But have you ever felt tired, grumpy, cranky, scatterbrained, lightheaded or irritable and notice these problems improve as soon as you eat?
In this case, your body is telling you that it needs food– just for whatever reason, the signal is not coming through your stomach. Instead of waiting for hunger pangs, start paying close attention to your overall mood. Are you quick to snap at someone? Are you finding it hard to concentrate at work? It may just be that it’s been a little too long since your last meal.
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Aging
A lack of appetite can be more common in older adults. In fact, between 15% and 30% of older people have less of an appetite than they used to. This can happen for a number of reasons.
- As you age, your digestion slows down, leading you to have a full stomach for longer periods of time.
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Your sense of smell, taste and vision gets weaker, making food less appealing.
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Hormonal changes or chronic illness can curb your appetite.
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Increased or decreased use of medications can contribute to a decreased appetite.
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Stomach Disorders
If you’ve recently noticed diarrhea, nausea, stomach pains or bloating after eating a meal, you may experience a loss of appetite. This is often associated with stomach disorders. Some stomach disorders that may have these as symptoms are:
- Irritable bowel syndrome
- Gallstones
- Constipation
- Food poisoning
- Giardiasis
- Chronic obstructive pulmonary disease (COPD)
- Gastroesophageal reflux disease (GERD)
- Food intolerances, such as lactose or gluten
- Colitis
- Crohn’s disease
How Does Adrenaline and The Process of Lipolysis Affect Your Appetite After Not Eating?
What adrenaline does is drive a process called lipolysis. This is the process your body undertakes when it wants to break down your fat reserves to give itself some energy. Lipolysis also prevents you from burning through your muscle when you don’t eat for a while.
Lipolysis likely occurs as an evolutionary function. Early humans did not have what we have today. There was no intense agriculture. People didn’t have easy access to food. Instead, we were hunter/gatherers, which means there would be periods where earlier humans just couldn’t access food.
That’s where lipolysis probably started kicking in for those early humans. Their bodies would burn through their fat reserves so that they could keep going during long periods. The elimination of hunger pangs that comes from this would distract from the issue and ensure the humans could focus on getting food rather than how much he or she needed food.
This is something most of us don’t experience today. You probably have access to food even if you don’t eat for a while. Even so, not eating triggers the same sort of response and your body goes into a sort of survival mode if it does not receive food over a long period of time. Adrenaline plays a key role in keeping that going until you eventually decide to eat.
See More: How Caffeine Revs Up Your Metabolism
Understanding the Link Between Blood Glucose Levels and the Loss of Appetite
It’s not just your fat reserves you need to think about. Not eating means your body doesn’t get the sugars it needs to operate properly. This leads to a process called gluconeogenesis, which also causes the loss of appetite.
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Gluconeogenesis is your body’s way of telling itself that blood glucose levels are too low.
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When you undergo gluconeogenesis, your body starts producing more of a hormone called glucagon.
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Glucagon increases blood glucose levels while also dropping insulin production.
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Gluconeogenesis causes your body to start breaking down fats and tissues, kind of like how adrenaline does.
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Studies show that gluconeogenesis increases the number of calories the body burns – with no carbohydrates coming in, the body creates its own glucose using mainly fat.
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Eventually, the body runs out of these energy sources and fasting mode then becomes the more serious starvation mode.
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At this point, your metabolism begins to slow down and your body will burn muscle tissue for energy.
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However, true starvation mode is not entered until 3 days straight of not eating.
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After 3 days, your body will start breaking down vital tissues and organs as it enters a deeper survival mode.
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Your body will not reach this point if you have only skipped 1 meal or have only gone 24 hours without eating.
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The result of not eating for more than 24 hours straight while undergoing gluconeogenesis will simply be that your body will break down the fatty acid reserves of fat in the body and around the organs and turn them into fuel.
What Does It All Mean?
In a recent study, results found that Basal Metabolic Rate didn’t decline until 60 hours of fasting. BMR is how many calories your body would burn if you were motionless for a day without food and accounts for the majority of your daily calorie burn unless you're very physically active. A separate study found that metabolism actually speeds up after fasting for 36 to 48 hours.
So, think of it this way – if you haven’t eaten anything in a while, you may experience hunger pangs. What is your body telling you? Probably to go find food. Our bodies encourage us to do that by flooding our tubes with adrenaline and triggers the release of glucose from energy stores, which makes our mind sharper and increases our basal metabolic rate.
The body is a powerful thing. It will take measures to halt further muscle loss because of its crucial role in keeping us strong and functional. Therefore, your body will not enter “starvation mode” until after about 3 days (72 hours) of not eating.
For many healthy adults, it’s not the worst thing in the world to occasionally skip a meal. But if you frequently reach the point where your hunger dissipates, here are some ways to increase your appetite in the long run.
Tips to Increase Appetite
If you frequently experience a loss of appetite, here are some strategies that can help increase your appetite over time:
- Change your eating habits (Ex. If you’re used to skipping breakfast, consider starting the day off with a nourishing meal).
- Eat nutrient-rich foods.
- Stock up on your favorite foods – you’ll find it’s much easier to eat something you really enjoy.
- Eat several, smaller portioned meals instead of a few large meals.
- Drink water between meals, not during.
- Exercise – physical activity releases brain chemicals that can improve your mood and stimulate your appetite.
- Get plenty of rest.
- Make mealtime an enjoyable social activity.
- Eat less fiber – diets high in fiber have been proven to promote feelings of fullness.
- Use carminative herbs and spices, such as peppermint, fennel, rosemary or parsley to help reduce bloating and improve your appetite.
Should I Eat Even If I’m Not Hungry?
Should you eat when you’re not hungry? Or better yet, when you’re not feeling hungry but know your body needs food, what should you do?
The right thing to do is to always eat when there is physiological/internal cue – in other words, when you either feel that hunger pang or become aware that your body is in need of a nourishing substance.There are two guiding factors of what to eat and how much.
1. Inner Wisdom
- It is subjective
- It is how the body lets us know that we need food, or have had enough to eat.
2. Outer Wisdom
- It is objective.
- It is knowing what your body needs even if it’s not exactly asking for it.
While it may be easier to identify hunger using inner wisdom, we cannot discount our outer wisdom. Outer wisdom is the knowledge to know that it’s been a little while since we last had something to eat and that our body needs food – even if it’s not showing any signs or hunger symptoms.
What To Eat When You’re Not Hungry?
After considering all the loss of appetite causes, you might decide that your lack of appetite is really nothing to worry about. You feel strong, you’re in a good mood and you’ve ruled out major causes like chronic disease. In that case, this feeling is completely normal.
However, a lack of appetite is not necessarily a sign that your body has enough food and doesn’t need more. It’s important to still eat even when you don’t feel hungry to make sure you are getting in the required nutrients to become the strongest you there is. For example, pregnant women would still need to eat in order to obtain those nutrients needed to support their body and their baby.
So, what to do?
- Choose calorie-dense foods, such as avocados and fatty meats. This way, you don’t have to scarf down a huge quantity of food when you don’t feel hungry.
- Consider making a fruit/vegetable smoothie that is high in vitamins, minerals and many other beneficial nutrients.
- Chug a glass of water to stay hydrated and refreshed.
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When you’re low on energy from either dieting or fasting and your glucose is low, consider an energy source packed with vitamins, such as Neuro’s gums and mints, to provide your body with needed vitamins like B6 and B12.
Conclusion
Experiencing a loss of appetite after not eating for a while can be attributed to various factors such as stress, illness, medication, aging, or stomach disorders. Understanding the underlying causes can help you address the issue appropriately. While it's essential to listen to your body's cues and eat when hungry, it's also important to recognize when your body needs nourishment, even if you don't feel the typical hunger symptoms. Incorporating healthy eating habits and making mealtime enjoyable can help increase your appetite. Remember to consult a healthcare professional for personalized advice if you have persistent or concerning appetite issues. For more information on the topic, check out our article, Chewing Gum make you less hungry! Explained by a Neuroscientist.
