The Link Between Nutrition and Your Child's Sleep (What the Research Says)

If bedtime in your house feels like a negotiation that stretches from 7pm to 9pm, with multiple curtain calls, one more drink of water, and a child who is somehow wide awake despite being exhausted all afternoon, I want you to know something.

It might not be behavioural. It might be nutritional.

As a nutritionist, I've always known that diet affects sleep. But it wasn't until I started formulating Kids Immune Protein and hearing back from thousands of families that I truly understood how significant the connection is for young children. Parent after parent telling me the same thing: "They're settling faster. They're sleeping deeper. Bedtime isn't a fight anymore."

So I want to explain why, because once you understand the science, it changes the way you think about your child's evening routine.

The science: what a 2023 study found

A 2023 study evaluating the dietary influence on childhood sleep found that children who consumed adequate protein and healthy fats throughout the day and in the evening were more likely to fall asleep faster and stay asleep for longer. The study also found that children with higher intakes of fast food and sugary drinks had significantly poorer sleep outcomes.

This isn't surprising when you understand how sleep works at a biochemical level. Your child's body doesn't just "switch off" at bedtime. It goes through a complex process of producing hormones and neurotransmitters that signal relaxation, drowsiness, and eventually deep sleep. And the raw materials for that process come from food.

Three nutrients that directly support sleep

Not all nutrients affect sleep equally. Three in particular play a direct role in helping children wind down, fall asleep, and stay asleep through the night.

L-Tryptophan: the sleep amino acid

Tryptophan is an essential amino acid, meaning the body cannot make it on its own. It must come from food. Once consumed, tryptophan is converted into serotonin (which regulates mood and calmness) and then into melatonin (which signals the body that it's time to sleep).

This is why foods like turkey, chicken, and dairy are often associated with sleepiness. They contain tryptophan. But here's the thing: most kids supplement powders don't contain any tryptophan at all, and collagen protein on its own doesn't naturally contain it either.

Many parents have told me they've noticed their child settling better at bedtime since starting Immune Protein. I believe the L-Tryptophan is one of the key reasons why.

Magnesium: the calming mineral

Magnesium is involved in over 300 enzymatic reactions in the body, but for sleep, its most important role is supporting muscle relaxation and calming the nervous system. Children who are low in magnesium can seem "wired" at bedtime, unable to physically relax even when they're tired.

Good food sources of magnesium include leafy greens, nuts, seeds, and whole grains. If your child is a picky eater who avoids most of these, magnesium is likely one of the nutrients falling short. Kids Immune Protein contains magnesium gluconate, and we also created Magnesium Hot Chocolate specifically as an evening routine product for families who want to lean into the sleep support angle.

Glycine: the collagen connection

This is the one most people don't know about. Glycine is one of the most abundant amino acids in collagen protein, and research has shown that glycine can improve sleep quality by lowering core body temperature and promoting relaxation.

Because Kids Immune Protein is built on a collagen base (62% of the formula), every serve delivers a significant amount of glycine. Combined with the added L-Tryptophan and magnesium, you have three sleep-supportive nutrients working together in a single product.

What parents are telling us

I want to share a few real reviews from parents who've noticed a difference in their child's sleep. These are unedited.

Practical tips for a sleep-supportive evening routine

The bottom line

Sleep is not just about routine and environment. It's about giving your child's body the raw materials it needs to produce the hormones that regulate sleep. L-Tryptophan for serotonin and melatonin production. Magnesium for muscle relaxation and nervous system calming. Glycine from collagen for body temperature regulation and sleep quality.

When I formulated Kids Immune Protein, I didn't set out to create a sleep product. I set out to create a complete nutritional foundation for growing children. But the sleep benefits have been one of the most consistent pieces of feedback we receive, and the science explains why.

If bedtime is hard in your house, try adding a protein-rich afternoon snack or an evening milkshake to the routine. It won't fix everything overnight, but it gives your child's body the best possible chance to do what it's designed to do: wind down, fall asleep, and stay asleep.

Nicola x

Related reading: Sleepy Time Gummies Recipe · Sleepy Time Cookies Recipe · Is Collagen Safe for Kids?