Signs of Hunger: Recognizing True Hunger & How Your Glucose Can Guide You

Can you tell the difference between true hunger and eating for other reasons? If not, you aren't alone. It turns out many people can't. Here's what to do about it.

Hunger Signals

What Is True Hunger?

True hunger is a physiological, sometimes uncomfortable response to a lack of food or nutrients. Oppositely, eating just because the food is available or because you suddenly can't stop thinking about your favorite ice cream can be confused for hunger. 

But eating for reasons other than true hunger is one of the reasons we overeat.

Recognizing hunger cues can help you eat in a way that nourishes your body and supports optimal health, but it can take work to retrain your brain to understand the different reasons you may feel like eating.

There are several ways to accomplish this, including mindfulness techniques and using metabolic markers like glucose (blood sugar) to understand your individual response to food and nutrients.

Let's dive into the science behind hunger, why you eat when you aren't hungry, and how you can use personal health data like glucose to drive lasting change.

Physiology of Hunger

Hunger is a physiological response to the absence of nutrients. Hormones that drive hunger like ghrelin are produced in the gut and signal to the brain to increase your appetite.<sup>1</sup>

Signs of hunger include:

  • Stomach growling
  • Headache
  • Low energy
  • Light-headedness
  • Stomach cramping or pain
  • Moody or irritable 
Infographic: Signs of Hunger - Stomach growling. Headache. Low energy. Light-headedness. Stomach cramping or pain. Moody or irritable.

Some of these signals occur just as you start to get hungry, while others may be a sign you've gone too long without eating.

You can tell if you are really hungry because nearly any food will satisfy you. Your body wants nutrients regardless of where they come from.

Food Cravings Vs True Hunger 

Oppositely, cravings are usually for a very specific food. Cravings are driven by emotions or even pleasure-seeking neurotransmitters in the brain, and foods high in sugar, salt, or fat make it much easier for your brain to crave more of these types of foods.<sup>2, 3</sup>

The more you eat that food, the more you crave it, and even just smelling or thinking about the food can trigger your brain to want it.4

Other Reasons You’re Not Hungry, but Want to Eat

Aside from cravings, there are a number of reasons people eat besides true hunger:

  • Boredom: Stuck at home with nothing to do can increase your trips to the fridge.
  • Stress: Feeling stressed can upregulate stress hormones that increase food cravings.
  • Sadness: Food becomes a comfort for some people who eat when dealing with uncomfortable emotions.
  • Habit: The clock says it's noon, so it must be lunchtime, even if you ate a late breakfast.
  • Social. If people around you are eating, chances are you will too, even if you aren't hungry.

Sometimes eating for reasons other than hunger is normal and okay, but if it happens regularly, or you feel like you can't even really tell when you are hungry or full, it's probably time to take a closer look at what's going on.

Infographic: Why we eat when we're not hungry - We have cravings. We're bored. We're sad. We have a routine. We're being social.

Why Are We Out of Sync with Hunger and Satiety Signals?

If hunger and satiety (fullness or satisfaction after meals) signals are built into our bodies, why and how did we lose touch with our natural biology?

There isn't one answer. Cues to eat come at us all day long from advertising on television to the scents of the local pizza place down the street. And if you've spent a lifetime ignoring hunger, swinging between diets that overly restrict calories with periods of overeating, it can be challenging to find that middle ground. 

But it's not impossible.

The Obesogenic Environment

Studies on why Americans struggle so much with weight often look at what's called the obesogenic environment.<sup>5</sup>

What Is the Obesogenic Environment?

An obesogenic environment is a combination of the factors that collectively promote obesity. All can influence food choices from physical environments, like the location of fast-food restaurants in proximity to where you live, to the accessibility of parks or areas to exercise.  

Altogether, we are constantly exposed to less-than-optimal food choices at every corner, making it easy to eat something before we've really had a conversation with our brain and stomach. Simply viewing certain foods can influence your desire to eat them.<sup>6</sup>

Restrictive Diets

But on the opposite side of the coin, many people have spent a lifetime jumping in and out of diet plans that are not meant to be long term, over restrict calories, and teach you to ignore your hunger cues. 

Why We’re So “Hungry” After Dieting

So what happens? You are more likely to overeat when you stop that diet because you are just so hungry. You may even experience anxiety if you go too long without food because you spent so much time with your stomach growling, ignoring the normal physiological response to hunger. 

Between these two scenarios, it's hard to know what full versus satisfied versus hungry even means anymore. 

Stop Eating When 80% Full

In Japan, the practice of hari hachi bu, which means to stop eating when you are 80% full, is associated with longevity and better health. But how many of us actually know what it means to stop eating at 80%?

4 Ways to Get Back in Touch with Hunger Cues

Regaining control of hunger and satiety cues takes practice. More than anything, it requires being mindful of what you put into your mouth and how your body feels. Here are a few tips to get started:

1. Use a Hunger Scale to Retrain Your Brain

One way to get back in touch with our missing hunger signals is to use a hunger scale. There's no one right way to rate your hunger or appetite. 

Some dietitians and health experts suggest using a 10-point scale with 10 being so full you feel physically ill and one being dizzy and painfully hungry. You can also rate hunger based on a smaller four-point scale where one equals not hungry at all and four equals full.

Signos Can Help Identify True Hunger

But if you’re just getting started with hunger cues, it can be helpful to have personalized feedback until you’re more confident in your ability to judge hunger. This is where apps like Signos, which connect your glucose data from a continuous glucose monitor (CGM), can help.

We are all familiar with a traffic light where green means go, yellow means slow down, and red means stop. Signos uses the same familiar visual cues to help you tie your glucose levels with hunger. The app provides individualized guidance based on your glucose readings.

If your blood sugar is still elevated from your last meal or snack, the app will let you know that you are still in a red or yellow zone (stop or slow down) and recommend you wait until you are in the green zone (go ahead and eat!). 

You can even set a timer for 10 or 20 minutes—whether you’re using the app or trying to do it yourself—to see if you are still hungry after that point. If your desire to eat is based on something other than true hunger, you may end up busy with another activity and no longer feel the need to eat.

With a hunger scale of any kind, you still have complete control. If you want to eat something, even if your glucose is still a bit high or you aren’t truly hungry, you absolutely can. But seeing the color-coded feedback, or thinking through where you land on the hunger scale are gentle, positive ways that you can work on eating in a way that benefits your health. 

2. Avoid Processed and Refined Foods

You likely know that highly processed foods full of sugar aren't great for your health, and one of the reasons is they can interfere with normal hunger cues. 

Eating more sugar, salt, and refined oils from processed foods can increase your desire to keep eating.<sup7</sup> Plus, foods high in refined sugar and carbs can spike your blood sugar, and when it comes back down, you are likely to crave even more simple carbs and sugar to bring blood sugar back up.

3. Eat More Protein and Fiber

Nutrients like protein and fiber are essential for blood sugar balance, impacting your hunger and cravings. Studies on protein conclude that it is the most satiating macronutrient—meaning it keeps you full and satisfied longer than carbs or fat.<sup>8</sup>

Fiber also slows down the glycemic response, keeping your blood sugar steady.<sup>9</sup>

4. Take Your Time While Eating and Remove Distractions

Put down the phone, turn off the television, and stay present with your food. Distracted eating can make it more likely you miss out on satiety cues, and it also makes it easier to eat quickly without really tasting your food.<sup>10</sup>

4 WAYS TO IDENTIFY HUNGER CUES - 1. Use a hunger scale; 2. avoid processed & refined foods; 3. Eat more protein & fiber; 4. Take your time when eating

Using Glucose to Guide Hunger Cues

Using your own biology as a way to connect the dots and understand the difference between true hunger signs versus cravings can be a powerful tool. 

Blood Sugar Is Closely Tied to Your Hunger

Glucose, the sugar in your blood, rises after eating carbohydrates and drops down between meals. This means that if you are reaching for something to eat and your blood sugar is still elevated from your last meal, it could indicate that you are eating for a reason other than hunger.

Drops in blood sugar are closely linked to hunger, as established by a study that used continuous blood glucose monitors along with perceived hunger to assess appetite. Results showed a close tie between low blood sugar between meals and appetite and energy levels.<sup>11</sup> Those with the most significant dips in blood sugar between meals also ate earlier and consumed more food than those with stable blood sugar. 

In another study, researchers found that people who eat without signs of hunger were more likely to be overweight and eat when blood sugar is still high. Oppositely, those with lower body sizes were less likely to perceive hunger at higher blood sugar levels, which likely means they could eat according to natural hunger cues instead of cravings or other reasons.<sup>12</sup>

Behavior Modifications Plus Glucose Monitoring Are Linked to Improved Hunger Signals

If blood sugar can help predict hunger, it could help people get back in touch with satiety signals. One way to do this is to test your glucose.

In one study, participants learned to estimate blood glucose at meals by linking feelings of hunger with blood sugar readings. By the end of the seven weeks, people in the study could successfully estimate blood sugar and hunger levels to make better choices.<sup>13</sup>

Similar results were seen in another pilot study on hunger cues in adults. Participants who used glucose monitors could match hunger to blood sugar by the end and reported feeling more aware of hunger and satiety.<sup>14</sup>

Since not all foods raise blood sugar, using glucose as a guide for hunger isn't the only way to assess and retrain your brain, but it can certainly be a part of an overall mindful way to get back in touch with your body.  

It's also important to note that these studies were conducted on people without blood sugar dysregulation. Someone with prediabetes or diabetes could have elevated blood sugar because of medical reasons, and it wouldn't necessarily indicate eating without hunger.

Still, for those without diabetes, glucose monitoring could be a powerful tool to get back in touch with hunger cues.

Finding Your Hunger and Satiety Cues Takes Practice

If you’re just getting started on the journey to finding your hunger signals, it can take time and practice, just like any other new habit.

If you unintentionally skip meals and find yourself starving before you eat, think about eating more regularly. Taste your food, pair your carbs with protein and fiber, and consider testing your glucose. Using glucose monitoring, along with a hunger scale and mindful eating practices, can all go a long way to helping you make changes.

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About the Author

Caitlin Beale Headshot
Caitlin Beale is a registered dietitian and nutrition writer with a master’s degree in nutrition. She has a background in acute care, integrative wellness, and clinical nutrition.
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Please note: The Signos team is committed to sharing insightful and actionable health articles that are backed by scientific research, supported by expert reviews, and vetted by experienced health editors. The Signos blog is not intended to diagnose, treat, cure or prevent any disease. If you have or suspect you have a medical problem, promptly contact your professional healthcare provider. Read more about our editorial process and content philosophy here.

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