Helping Teens Understand Real Nutrition
Nutrition and You: Fueling the Teenage Body
One of the most important aspects of healthy living is proper nutrition. Nutrition impacts every bodily system and function, from muscular development to energy levels to attentiveness. Therefore, it is essential to maintain the levels of nourishment necessary to keep our bodies in working order, especially for adolescents who have the added strain of puberty drawing on their energy reserves.
Unfortunately, a lot of teens go through their day chronically malnourished. Teen hunger is difficult to quantify, but it is estimated that around 14 million children in the United States are not eating amounts adequate to meet their daily nutritional requirements. Reasons for this vary; poverty and hunger are significant factors. However, for many adolescents, malnourishment can be the result of poor dietary choices, unhealthy relationships with food, and eating disorders.
For kids where poverty is not an issue, often the culprit is a misunderstanding about the role appetite plays in triggering hunger signals in the body. Today, we will discuss understanding appetite a bit.
Reasons Why Young People May Be Malnourished
First, what is chronic malnourishment? Someone is chronically malnourished if they habitually eat fewer calories per day than the body needs for healthy maintenance and growth. Malnourishment is not a matter of having one or two off days now and then. It’s a condition brought about by routine undereating over a prolonged period. There are many reasons teens may be malnourished: skipping meals because of busy schedules, poor food choices (e.g., eating a bag of chips for lunch instead of something more nutrient-rich), or eating portions that are too small. For example, having a meal that consists of nothing more than a handful of berries. Caffeine is also a hunger suppressant. Teens who drink a significant amount of coffee, tea, or soda throughout the day may go for prolonged periods without eating.
It is entirely possible for young people to be in a state of malnourishment without realizing it. A lot of this comes down to misunderstanding the role of appetite and how it relates to nutrition. I once heard a teenage girl say she had eaten nothing but a small apple the entire day. When I asked her if she really thought that was sufficient, she replied, “Oh, it’s okay, I wasn’t hungry.” Since her appetite wasn’t triggering hunger signals, she assumed it was all right that she had barely eaten.
This is a common misunderstanding of what appetite is for. Let’s talk about your appetite and why, if you struggle with food, you should still be eating even when you’re not hungry.
How Appetite Works
While we associate the appetite with eating, it is important to understand that, strictly speaking, the appetite does not tell you when you are supposed to eat. The appetite merely reminds you of what your current eating routine is. Let’s talk about how the appetite works.
The appetite is triggered by a hormone called ghrelin. Ghrelin is released when your stomach is empty, which certainly tells you it’s time to eat. However, it is also released according to the frequency with which you usually eat. If, for example, you normally eat three times a day in the morning, noon, and night, ghrelin levels will correspondingly increase in the morning, noon, and night because that’s your eating routine. It is the way your body says, “Hey, you normally eat now.” Appetite thus acclimates itself to whatever eating schedule you are on.
But if your routine is different, the ghrelin will acclimate to that routine. So, if you habitually don’t eat except for a few scraps of food each day, the brain will barely release any ghrelin because you barely eat.
When Hunger Lies
This means that while appetite can signal when it’s time to eat, it shouldn’t be the sole guide for your eating schedule. In fact, it’s often the schedule that shapes your hunger cues, not the other way around. Hunger can be deceptive. For example, individuals struggling with obesity may continue to feel hungry even when their bodies don’t need more calories. Why? Because a frequent eating routine trains the body to expect food at those times. The appetite responds not to caloric need, but to habit, prompting hunger simply because it’s “time to eat,” not because fuel is needed.
Conversely, there are people who seldom eat and are never hungry, even though they need more calories. This was the case of the young woman I mentioned above, who went most of the day on a single apple and never experienced hunger. You can literally be in a state of moderate starvation and not experience hunger.
The purpose of your hunger isn’t to say, “We need to eat right now!” It’s to say, “Hey, you usually eat right now.” Your appetite will change based on your routine. If your routine is to be underfed, your appetite will reflect this. This is why you can’t only go by your appetite to discern when and if you should eat. Resetting your appetite’s internal schedule can take time, sometimes several months. So, be patient with yourself.
Caloric Needs for Teens
While hunger is one determinant of when we should eat, it is very important to be cognizant of the body’s caloric needs. Most teenagers need between 2,000 and 3,000 calories per day. Athletes, especially boys (source), may need more. If you are concerned that your teen is malnourished, it is essential to roughly monitor the number of calories they consume and ensure your child is getting the right amount throughout the day. Ideally, these should be a mix of macronutrients (proteins, carbs, healthy fats).
Many people are unaware of the low calorie content in certain foods. For example, I occasionally hear teens saying, “I ate a half an apple and a muffin for breakfast,” and then that’s all they will eat until dinner. An apple has about 80 calories, so half an apple is maybe 40. And a muffin (depending on the size) might be 200-300 calories. So that’s maybe 340 calories at the most. Then they will eat a small dinner and call it good. A teen on such an eating schedule would be 1500 calories in the negative for the day. Repeating this day after day would result in serious malnourishment.
Of course, bodies are resilient, and people can force themselves to keep going, but there is a cost for everything; the body will pull extra energy from other functions to make up for the energy deficit. A teen who is malnourished, for example, may be groggy, struggle to focus, lack energy, lack motivation, and fight to concentrate. If your teenager laments that she struggles to concentrate and focus on school, look at her nutrition levels. I see many adolescents complain about a lack of focus, but they eat at barely subsistence levels and don’t seem to realize the correlation.
Fuel Up!
Beyond just eating enough, what teens eat matters deeply. Whole, nutrient-dense foods—such as fruits, vegetables, whole grains, lean proteins, and healthy fats—fuel the body in ways processed and sugary foods simply can’t. Processed snacks and sugary drinks may offer a quick burst of energy, but they often lead to crashes in mood, focus, and stamina. Whole foods, by contrast, provide sustained energy, support hormonal balance, improve mental clarity, and help the body grow and repair effectively, especially vital during the adolescent years when bodies and brains are rapidly developing. Encouraging teens to build meals around real, whole foods is one of the most impactful steps parents can take toward lifelong health.
In Summary
Understanding the mechanics of appetite and the realities of teen caloric needs is critical to supporting adolescent health. Teens may be malnourished not because of access, but because of misunderstanding their body’s signals or routines that suppress hunger cues altogether. Appetite, shaped by habit more than need, can mislead both teens and parents. By tuning in to nutritional needs rather than just feelings of hunger, and by prioritizing whole foods over empty calories, we can help teens build habits that sustain energy, sharpen focus, and promote lasting well-being. In the end, healthy eating isn’t just about food—it’s about fueling the whole person for growth, learning, and life.
Nutrition is essential to our lives, and relationships with food can be complex and multifaceted. The long and short of it is this: appetite isn’t the sole determinant of when we should eat. Think in terms of calories and fuel. “Fuel up” if you know you need more, and as eating schedules are readjusted, the appetite will also readjust itself.
What would you like to add to this conversation? To share your tips, experiences, and questions, you can join me and other homeschoolers in the Homeschool Connections Facebook Group. I would love to hear from you!
Editor’s Note: If you would like to learn more about health and nutrition, Homeschool Connections offers middle and high school health science courses for homeschoolers.
