Why Junk Food is Unhealthy for Kids


In today’s world, junk food is everywhere. It’s convenient, tasty, and often cheap. For busy parents especially, it can seem like an easy option to feed the kids. However, regularly fueling our children’s growing bodies with heavily processed, nutrition-poor junk foods can have serious health consequences that last into adulthood.

As parents, we want to set our kids up for healthy, happy lives. Part of doing that involves teaching nutrition and promoting healthy eating habits from a young age. Understanding why junk food is detrimental to kids’ health is an important first step toward limiting its consumption. In this comprehensive guide, we’ll examine the myriad reasons junk food is unhealthy for kids.

What is Junk Food?

Before diving in, let’s clarify what exactly counts as “junk food.” Junk foods are those that are typically high in calories, fat, sugar and salt, yet offer minimal nutritional value. They are also highly processed and contain numerous additives. Here are some examples of common junk foods:

  • Chips, crackers, and other salty snacks
  • Cookies, candy, ice cream, and other sweets
  • Fast food like burgers, fries, chicken nuggets, and tacos
  • Sugary cereals, waffles, and pancakes
  • Sugary beverages like soda and fruit juice
  • White breads and pastries made from refined flour
  • Microwave or frozen meals high in salt and preservatives

As you can see, junk food encompasses a wide variety of food types. They all have in common a lack of nutrients and an abundance of calories, processed ingredients, chemical additives, and substances like sugar, salt and unhealthy fats. Now, let’s explore why that’s so bad for growing kids.

High in Calories, Low in Nutrients

A defining quality of junk food is its high calorie count coupled with minimal nutritional value. Let’s break this down further:

  • Calories – Junk foods are often extremely dense in calories. For example, just a single cookie can contain over 100 calories and a small order of french fries over 300. Kids need calories to fuel growth and development, but they need the bulk of them to come from nutritious whole foods that also provide vitamins, minerals, fiber and more. Junk food calories are known as “empty” calories because they provide little beyond energy.
  • Lack of Nutrients – Junk foods contain few beneficial nutrients that kids require on a daily basis. This includes things like protein for building strong muscles, calcium for developing bones, iron for healthy blood, and vitamins A, C, and D for eyesight, immunity, and much more. Constantly filling up on junk foods can lead kids to become underweight or malnourished because their nutritional needs aren’t being met.

Junk foods aren’t just lacking in nutrients either; they actually displace healthier foods in kids’ diets. A child who inhales a 650-calorie fast food meal will have little appetite left for the home-cooked dinner with lean protein, veggies, and whole grains their body needs. Prioritizing junk food leads to nutritional deficiencies.

Health Dangers of Excess Sugar, Salt and Fat

Beyond empty calories and lack of nutrition, the actual substances in junk food pose health risks to kids. Let’s explore the big three: sugar, salt and unhealthy fats.


  • Naturally occurring sugars like those in fruit are fine for kids. But much of the sugar in the modern diet comes from added sugar in junk foods.
  • High sugar intake is linked to cavities, asthma, obesity, diabetes, and more. The sweet stuff provides no nutrients and excessive calories.
  • WHO recommends limiting added sugar to <10% of calories. Most U.S. kids exceed this. Excessive sugar taxes the body and brain.


  • Sodium is needed in small amounts, but junk food contains excessive amounts.
  • High salt intake raises blood pressure, putting strain on kids’ hearts. It may also blunt taste buds.
  • Junk food makes up a whopping 75% of sodium in kids’ diets. Children require less salt than adults.
  • Excess sodium increases risk of heart disease and stroke over time. Kids’ developing bodies are sensitive.

Unhealthy Fats

  • The fats found in junk foods like chips, fast food, baked goods and frozen meals are usually unhealthy trans or saturated fats.
  • These fats raise LDL (“bad”) cholesterol levels in the blood, increasing risk for heart disease.
  • Saturated and trans fats also contribute to inflammation, obesity, and other chronic diseases when eaten in excess.
  • Healthy unsaturated fats that support the body are lacking in most junk foods.

As you can see, junk foods contain a toxic cocktail of sugar, salt and bad fats guaranteed to negatively impact children’s health over time.

Addictive Nature of Junk Food

Have you ever wondered why kids seem programmed to crave junk food over nutritious fare? There are physiological reasons for those intense sugar and salt cravings.

Junk food is highly palatable due to carefully engineered combinations of fat, sugar and salt. Kids’ taste buds can’t resist calorie-dense, super sweet and salty foods. These substances actuallylight up the pleasure centers of developing brains.

Additionally, sugar stimulates the release of dopamine in the brain’s reward pathway. This makes kids feel good when they eat sugar-loaded junk foods. As time goes on, they may develop behavioral issues or a true addiction to these substances.

Of course, the aim of junk food manufacturers is to get consumers hooked on their products from a young age. Many fast food chains offer kids’ meals toys and popular media tie-ins. This further drives junk food consumption among children. Kids beg parents for these foods due to both physiological cravings and marketing tactics.

Health Consequences of Junk Food Diets

Now that we’ve covered why junk foods are unhealthy for kids, let’s look at some of the effects regular consumption can have:


  • Childhood obesity rates have skyrocketed, largely due to overconsumption of junk food. Obesity puts kids at risk for heart disease, diabetes and psychosocial problems.


  • Kids filled up on junk foods often consume far less than recommended amounts of important nutrients. This can impair growth and development.

GI Issues

  • Heavily processed junk foods can cause stomach upset, constipation, diarrhea and inflammation in kids’ sensitive digestive systems.

Tooth Decay

  • The sugars and acids in junk food literally rot tooth enamel. Kid cavities related to sugary junk foods are on the rise.

Behavioral Problems

  • Studies link junk food to poor concentration, impulsivity, hyperactivity and mood swings in children. ADHD symptoms may worsen.

Metabolic Changes

  • Excess junk food consumption changes metabolism to promote fat storage. This makes healthy eating and weight management more difficult.

Sleep Disruption

  • Junk food messes with blood sugar regulation, which can impair sleep quality and quantity in kids. Lack of sleep tends to increase junk food consumption.

Immune Impairment

  • Nutrient deficiencies combined with excess sugar intake weaken immunity. Kids who overdo junk foods get sick more often.

As you can see, regularly eating junk foods can impact children from head to toe, inside and out. And poor health in childhood tends to carry over throughout life.

Setting Kids Up for Healthy Eating Habits

Now that you know how detrimental junk food can be for kids, what’s a parent to do? It’s unrealistic to completely ban or restrict all junk foods. The key is moderation. Consider these tips:

  • Limit junk food to once a week or special occasions only
  • Offer healthy snacks like fruits, veggies, yogurt and nuts for everyday
  • Encourage kids to stop eating when full by removing plates
  • Avoid using junk food as a reward
  • Let kids choose and help prepare healthy foods
  • Be a role model by eating well yourself
  • Gradually transition kids’ palates by reducing sugar and salt
  • Focus on getting enough protein, fiber and healthy fats
  • Stay hydrated with water and limit soda/juice

Starting healthy habits in childhood will make a lifelong impact. Sheltering kids from ever seeing or tasting junk food isn’t the answer. A better approach is teaching moderation, nutrition knowledge, and how delicious and satisfying healthier fare can be. With patience and consistency, your kids can learn to love wholesome foods.


In many ways, junk food seems specially engineered to appeal to kids with its fun flavors, shapes and marketing ploys. However, regularly fueling growing bodies with sugar-laden, nutrient-poor junk foods has real health consequences that last a lifetime. While the occasional indulgence won’t cause harm, making junk a regular thing can negatively impact children’s health, behavior, immune function, and even their eating habits as adults. By understanding junk food’s dangers along with tactics to promote nutrition and moderation, parents can set their kids up for healthy, happy lives.

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