Hunger is complicated and can have many different triggers, said Dr. Monique Tello, a clinical instructor at Harvard Medical School, practicing physician and director of research and academic affairs for the healthy lifestyle program at Massachusetts General Hospital.
Medical reasons:
First, it’s important to rule out any medical issues. Anybody who is feeling very hungry all of the time and isn’t able to gain weight or is losing weight should see a doctor, Tello said.
Conditions that could cause constant or excessive hunger, also called polyphagia, include:
Hyperthyroidism: When the thyroid is overactive, a person’s body and metabolism are “all revved up,” Tello noted. Besides being hungry, patients feel jittery, shaky and their heart may be racing.
Diabetes: People with type 1 diabetes lose the ability to make insulin so their body can’t process sugar. “They’re usually telling me: I’m eating and eating, I’m losing weight and I feel terrible,” Tello said.
Damage to the hypothalamus: This part of the brain helps regulate feelings of appetite and satiety. If it’s damaged because of a tumor or head trauma, it can cause uncontrollable hunger and hypothalamic obesity.
Psychological reasons:
If there isn’t an underlying medical issue, the problem could be in the head.
It’s reasonable to be hungry every three to five hours given how the human digestive system works. But ever-present food marketing on TV and the constant stream of “food porn” on social media can trigger people to eat often and a lot.
There are also deeply ingrained cultural triggers, like the idea of eating three meals a day plus snacks, Tello said. She hates the “myth of breakfast” — or the notion people have to eat as soon as they wake up.
“I tell patients, ‘The more you eat, the more you want to eat,’” Tello said.
“The more people eat, the larger the stomach gets. The stomach can stretch to accommodate large amounts of food — it’s a distensible organ. Then if it’s empty, it signals hunger. Well, if you’ve got a huge stomach from eating so much so often, the minute your stomach is empty, it’s signaling you to eat and you’re going to eat more.”
A person’s state of mind can play a role, too. Stress can increase levels of ghrelin, research has shown, and being sleep deprived is associated with higher levels of the hunger hormone.
Boredom, anxiety and depression can also send people looking into the refrigerator when they’re not truly hungry.
Lifestyle reasons:
Sometimes the best answer to the question “Why am I always hungry?” is the simplest one: You’re eating too little, exercising too much, or both.
Solutions:
Don’t make yourself hungrier than you need to be: Limit your exposure to TV and social media. Try to watch your favorite shows without being exposed to advertising, Tello said.
Get honest: Ask yourself, "Am I really hungry? Or am I bored?" Remove yourself from any food temptations if it's the latter.
Consider intermittent fasting: It can reconnect you with true, biological hunger; make it easier to recognize feeling full.
Feel fuller by adjusting the quality of your diet: Avoid processed carbohydrates and sugars found in foods like white bread, baked goods and cereal. Aim for a satiating diet higher in fiber, protein and healthy fats, Tello advised. Such choices will keep you more satisfied, longer.
Watch your alcohol intake: Alcohol lowers a person's inhibitions and self-discipline, which can make you eat more.