Feeling hungry isn't a bad thing. It's your body's way of telling you it needs fuel to function. But if you feel famished all the time – even after finishing a meal – easily remedied mistakes may be to blame, some which may surprise you.
Hunger is a biological drive to eat that's associated with a grumbling stomach, weakness and/or headache, symptoms that can undermine your concentration and prompt you to make less-than-stellar food choices. Appetite, on the other hand, is the desire to seek out a specific food, whether you feel hungry or not.
When your stomach is empty, it secretes ghrelin, a hunger hormone that signals your brain it's time to eat. Your brain, in turn, increases hunger and stimulates the release of stomach acid to prepare your body for food intake. When you've had enough to eat and your stomach is stretched, it stops churning out ghrelin.
How often you should feel hungry depends largely on what – and when – you last ate. In general, though, it's normal to feel hungry, or a little peckish, three to four hours after eating a meal.
If you find yourself hungry more often than this – or ravenous before meals – consider whether one (or more) of the following culprits is the reason.
You eat too little protein (or fat)
Including a source of protein – e.g., chicken, fish, lean meat, eggs, tofu, beans and lentils, yogurt, milk – at meals and snacks can delay hunger and fend off cravings. Protein stays in the stomach longer than other nutrients, so it promotes a feeling of fullness.
Fat also helps you feel satiated after eating. Include a source of heart-healthy unsaturated fat from oils, avocado, nuts, seeds or nut butter in each meal.
You're stuck on white bread
Highly processed carbohydrates in white bread, white rice, refined breakfast cereals, cookies, pastries and candy are digested quickly, causing your blood sugar (glucose) to rise rapidly. In response to high-glycemic carbohydrates, your insulin level soars, causing your blood glucose to drop and your brain to signal hunger.
Fibre-rich whole grains and some starchy vegetables, on the other hand, help to stabilize blood glucose. Replace refined grains with low-glycemic foods such as 100-per-cent whole-grain breads and breakfast cereals, oatmeal, brown rice, barley, quinoa, sweet potatoes and beans and lentils. Their fibre also adds bulk to meals which helps keep you feeling full longer.
You skimp on breakfast
Skipping the morning meal can trigger cravings, hunger and overeating later in the day by increasing ghrelin levels.
Missing breakfast or forgoing carbohydrates at the meal also causes serotonin to drop, which, in turn, can rev up your appetite, especially for sweets. (Serotonin, a chemical produced in the brain and the gut, helps regulate appetite, digestion and mood.)
A satisfying breakfast should include protein (e.g., eggs, Greek yogurt, soy milk), low-glycemic carbohydrates (steel cut oats, bran cereal, whole-grain rye bread, most types of fruit) and healthy fat (nut butter, chia seeds, flax meal).
Research suggests people often confuse thirst with hunger, perhaps because both sensations are regulated by brain's hypothalamus. Not drinking enough water can also make you feel tired and, as a result, turn to food to boost energy.
If you feel hungry soon after eating, drink a large glass of water and wait 20 minutes. If your hunger pangs persist, eat a healthy snack, perhaps one that provides water, too. Hydrating fruits include strawberries, watermelon, cantaloupe, peaches, raspberries, apricots and blueberries. Cucumber, celery, carrots, zucchini and spinach also have a high water content.
The hunger-suppressing effect of water may even help you slim down. Studies have found that dieters who drank two cups of water before meals were less hungry and consumed fewer calories at the meal.
Women require 9 cups (2.2 litres) of water each day; men need 12 cups (3 litres). All beverages, with the exception of alcohol, count towards daily water requirements.
You don't snack
If your meals are longer than four to five hours apart, include a small snack to prevent large dips in blood glucose – and to avoid feeling ravenous at meal time. Between-meal snacks should include protein and low-glycemic carbohydrates.
Good choices include fruit and nuts, yogurt and berries, whole-grain crackers and tuna or a homemade smoothie made with milk or soy milk and fruit. To control calories, keep snacks to 150 to 250 calories.
You're a fast eater
When you eat quickly, you don't give your brain enough time to register you've had enough to eat, even if your stomach is full. Eating slowly allows appetite-related hormones to kick in and tell your brain it's time to stop eating.
To slow your eating pace, pause between bites; put down your knife and fork and chew thoroughly. Ban distractions that prevent you from paying attention to the fact you're eating. Step away from the TV, computer or newspaper when eating.
You're stressed out
Continued stress increases adrenaline and cortisol, stress hormones that trigger a prolonged release of ghrelin. Plus, stress reduces serotonin, which can also make you feel hungry.
If you typically reach for sugar when feeling stressed, your blood glucose will peak and then crash, adding to your need for food. If you can't control your stress, control what you feed it.
You're short on sleep
Not getting the recommended seven to nine hours of sleep each night can drive hunger and sugar cravings during the day. Like chronic stress, too little sleep increases cortisol and raises ghrelin.
Feeling tired after a poor night's sleep can also send you in search of food for a boost of energy, even if you don't feel hungry.
Your appetite, not hunger, may be driving your desire to eat. Use the following scale to rate your hunger level before, during and after meals. You've had enough to eat when you feel satisfied, not full.
1. You feel starving. You can't concentrate and need food now.
2. You feel hungry, but you could wait a few minutes before eating.
3. You feel slightly hungry. You could eat something, but not a large meal.
4. Your hunger has almost disappeared. You could eat another bite, though.
5. You're no longer hungry. You feel satisfied, not full.
6. You feel slightly full.
7. You feel overly full and uncomfortable. Your waistband is noticeably tighter.
8. You feel stuffed, bloated, even a little nauseous (e.g. "Thanksgiving Day" full).
Leslie Beck, a registered dietitian, is based at the Medisys clinic in Toronto.