From a grumbling stomach to a splitting headache, we all know what it feels like to be really, really hungry. But if you're hungry even after eating a meal, you might have to do some digging to find out why.
The reasons we feel hungry are varied, and sometimes the instinct to eat has little do with food. Although hunger is an important cue for our bodies to refuel and get the energy we need to survive, at times hunger can mean we're just not getting the right nutrients, or it could even be psychological — a way to cope emotionally with boredom and stress.
So how can you figure out what your body is trying to tell you? These eight scenarios below might help clue you in.
1. You're Not Sleeping Enough
The next time you reach for a bag of corn puffs, ask yourself if you might need a nap instead.
According to the National Sleep Foundation, adequate sleep is between seven and nine hours per night, depending on the person. Any less than that results in a short-term spike of the hormone ghrelin, which boosts appetite, as well as a drop in leptin, which decreases it.
Plus, a September 2019 study published in the Journal of Lipid Research found that four nights of consecutive sleep restriction can cause people to metabolize food differently, leaving them hungry even after eating a meal.
2. You're Dehydrated
"A lot of people start feeling lethargic and lightheaded and think they need food, but they're really confusing hunger for thirst," says Bonnie Taub-Dix, RDN, a registered dietitian based in New York.
Drinking 64 ounces of water every day is "a good place to start" for hydration, says Taub-Dix, but some people may need more fluid if they're working out or live in a hotter climate.
3. You're on a Fad Diet
It's no great mystery that drastically restricting calories in order to lose weight might result in you feeling hungrier than normal. But the reason for this, says Taub-Dix, isn't just because people are eating less when they're dieting — it's because fad diets often cut out food groups altogether, such as protein, carbs or fat.
Each of these food groups contain important nutrients that promote satiety, Taub-Dix says, such as protein from meat sources or fiber found in carbohydrates. "I've never really seen a fad diet that encourages balance," Taub-Dix says. "And when you have a diet that's unbalanced with protein, carbs and fats, you're going to feel hungry."
4. You're Bored
If you're watching TV and find yourself mindlessly reaching for a bag of pretzels, consider that you might be snacking out of boredom, not hunger.
In a study published in the April 2015 issue of Frontiers in Psychology, researchers asked study participants to keep a food journal for one week, logging what they ate and when. The study found that participants were more likely to eat during periods of boredom — and that they gravitated toward unhealthy fats and carbohydrates.
The solution? When you get the urge to munch, try going for a walk or calling a friend instead.
5. You're Breastfeeding
Sometimes, hunger arises because your body is busy making food for another person. "The process of creating milk — which is, in itself, a food — increases nutrient and fluid demands because you're using your own fat stores and energy reserves," says Monica Auslander Moreno, RD, LDN, the Miami-based founder of Essence Nutrition. This means that the body is working hard and needs additional calories to make up for what it's burning, usually resulting in a feeling of intense hunger.
Guidelines say that nursing moms require anywhere between 300 and 500 calories above their pre-pregnancy needs each day while they're breastfeeding to produce enough milk and keep the hunger pangs at bay.
6. You Did a Tough Workout
Anyone who hits the gym regularly will tell you that working out makes you hungry — but the science behind exercise and hunger can be complicated. One early study, published in the January 2009 issue of the American Journal of Physiology, found that aerobic exercise and weight resistance both decreased a hormone called ghrelin, which effectively suppresses appetite. However, Moreno says, that's only for the short term: Exercising also depletes glycogen stores within the muscles, leaving you hungrier later.
What's more, according to the American Council on Exercise, failing to replenish your fluids adequately before and during exercise can result in dehydration, which can leave you feeling even hungrier than you normally would post-workout.
7. You're Not Getting Enough Fiber
While too much fiber in your diet might mean gas, bloating and constipation, not enough fiber means your stomach will likely be left grumbling — a lot.
"A diet low in fiber can definitely leave you hungry," says Moreno, since fiber slows the digestive process, leaving food in the stomach for a longer period of time and giving us the feeling of satiety.
8. Your Diet Has Too Much Salt
In 2017, a study published in the Journal of Clinical Investigation found that high-sodium diets actually increase hunger in the long term. The reason, researchers found, is because high-sodium diets — more than 12 grams per day — cause the body to retain fluid, which requires more energy and calories to store.
In addition, Moreno says, "High-salt foods also tend to be processed, and a lot of processed foods are chemically engineered to be hyper-palatable and cause overeating."
- Journal of Lipid Research: "Four nights of sleep restriction suppress the postprandial lipemic response and decrease satiety"
- Frontiers in Psychology: "Eaten up by boredom: consuming food to escape awareness of the bored self"
- American Journal of Physiology: "Influence of resistance and aerobic exercise on hunger, circulating levels of acylated ghrelin, and peptide YY in healthy males"
- National Sleep Foundation: "The Connection Between Sleep and Overeating"
- The Journal of Clinical Investigation: "Increased salt consumption induces body water conservation and decreases fluid intake"
- American Council on Exercise: "Healthy Hydration"