Fast food is everywhere and has become increasingly popular, especially among adolescents. In many neighborhoods across Los Angeles and Orange County, it is often easier to find a burger chain than a grocery store with fresh produce. It is quick, cheap, and tasty, making it a go-to choice for busy parents and hungry teens.1
While it is marketed as convenient and delicious, fast food often lacks the nutrients children need to grow and become healthy adults. Most fast food is ultra-processed, meaning it is made in factories with artificial ingredients, extra salt, and refined sugars to make it last longer and taste "addictive."2
What is in Fast Food?
The term “fast food” refers to meals prepared and served quickly and consistently. Fast food is more than just McDonald’s and Burger King. In general, fast food is defined as being:
Highly processed and mass-produced
High in sodium (salt) and unhealthy fats
Low in fiber, vitamins, and minerals that the body needs
Filled with preservatives and additives 2
How Fast Food Affects Your Child’s Body
When children eat fast food regularly, it affects their body systems all at once, from their hearts to their brains.
Heart and Blood Pressure
To make food stay fresh, companies pack it with sodium (salt).
The Problem: Children’s bodies are smaller and more sensitive to salt. Too much sodium makes the heart work harder and raises blood pressure.
The Risk: Over time, this stress can stiffen blood vessels, increasing the risk of heart attacks or strokes later in life.4
Blood Sugar and Energy
Fast food is full of "refined carbs" and added sugars that enter the bloodstream almost instantly.
The "Crash": This causes a sharp spike in blood sugar, followed by a quick "crash."
The Result: Instead of having steady energy for school, kids may feel tired, "cranky," or hungry again shortly after eating.4 Frequent spikes can eventually lead to Type 2 Diabetes, as the body stops using insulin correctly.2
The Brain and Mood
What children eat affects how they feel and learn.
Mood: Diets high in processed foods are linked to higher levels of anxiety, irritability, and depression because the brain isn't getting "brain foods" like antioxidants that help the brain clear out waste.
School Performance: Studies show kids who eat more fast food may score lower on exams. This is often because they lack iron, which is critical for memory and concentration.3
Understanding the Labels
You don't always have to avoid fast food entirely, but you should know what to look out for.
If you are checking a package or an online menu, use these Quick Rules of Thumb
Look for (and avoid)… | Why? |
Long ingredient lists | If it has unfamiliar chemical names, it is likely highly processed. |
Words like “emulsifiers,” “preservatives,” “artificial flavors,” and “stabilizers” | These are common in ultra-processed foods and are indicators of lower nutritional value. |
"Instant" or "packaged" | These are signs of added preservatives and lower nutritional value.2 |
Sodium levels | Aim for lower salt options to protect your child's heart. |
Simple, Healthier Choices
The ease and cost of fast food are hard to resist, but making changes doesn't have to be expensive. Small shifts in habit can protect both your child’s health and your wallet.
The Power of "Side Swaps": Instead of fries, ask for a side salad or fruit cup if available. Adding vegetables provides fiber that helps counteract the "sugar crash." Changes like this can add vitamins and minerals that help your child’s brain develop while improving mood and academic achievement.3
Choose Grilled over Fried: Grilled chicken has less unhealthy fat than breaded, fried nuggets and tastes just as good.
Water is King: Skip the soda. Fast food meals are already high in sugar. Drinking water helps flush out extra sodium and keeps your child hydrated without giving them extra “empty” calories.
Your child doesn't need special or expensive "fast" drinks and meals to be healthy. For everyday growth and school performance, simple foods and water are exactly what their bodies need.
Does your child usually prefer a specific type of fast food, like burgers or tacos, that we could help find a healthier alternative for? Let us know!
Sources:
1. Jia, P., Xue, H., Cheng, X., Wang, Y., & Wang, Y. (2021). Fast-food restaurant, unhealthy eating, and childhood obesity: A systematic review and meta-analysis. Obesity Reviews, 22(S1), e12944. https://doi.org/10.1111/obr.12944
2. Khoury, N., Martínez, M. Á., Garcidueñas-Fimbres, T. E., Pastor-Villaescusa, B., Leis, R., de Las Heras-Delgado, S., et al (2024). Ultraprocessed food consumption and cardiometabolic risk factors in children. JAMA Network, 7(5), e2411852 https://doi.org/10.1001/jamanetworkopen.2024.11852
3. Monteiro, C. A., Cannon, G., Levy, R. B., Moubarac, J.-C., Jaime, P., Martins, A. P., et al (2022). Ultra-processed foods: what they are and how to identify them. Public Health Nutrition, 25(4), 936–941. https://doi.org/10.1017/S1368980022000196
4. Cleveland Clinic (2021). Here’s how fast food can affect your body. Cleveland Clinic Health Essentials.
https://health.clevelandclinic.org/heres-how-fast-food-can-affect-your-body