2 to 5 year olds may be small, but they're growing and need the energy (calories) and nutrients that come from a varied and balanced diet. If your child is underweight, they may not be getting enough calories.
If you're concerned that your child is underweight or not growing normally, see a GP. A low weight can happen for several reasons.
How can I tell if my child is underweight?
As a parent, it can be difficult to tell if your child is underweight.
If you already know your child's height and weight, and want to know if they're a healthy weight for their age, height and sex, you can check using our BMI healthy weight calculator.
If your child is in reception (ages 4 and 5), they may have already been weighed and their height measured as part of the National Child Measurement Programme.
In some areas you may be sent the results for your child. In other areas you will have to contact your local authority to find out your child's measurements.
If results show that your child is underweight, talk to a GP, who can help to find the possible causes.
If there is a problem with your child's diet, the GP can provide advice that will help your child get to a healthy weight, or refer them to a dietitian.
What your child needs
All children need the energy (calories) and nutrients that come from a varied and balanced diet.
A healthy diet for a young child is not the same as a healthy diet for an adult. Many of the "healthier alternatives" that adults are advised to eat are not suitable for toddlers and young children.
Children have smaller stomachs than adults and need to eat smaller amounts more often. Eating 3 meals a day plus 3 smaller snacks at regular times is typical.
If your child is underweight, it might be tempting to give them high-calorie but unhealthy foods, such as sweets, chocolates, cakes, sugary drinks and fatty foods and drinks. But a varied, balanced diet is the key to a child's healthy weight gain.
What is a balanced diet?
A balanced diet for a young child means having a variety of foods that follows the Eatwell Guide. From the age of 2, a child should begin to eat a diet that is like the rest of their family's, in line with the Eatwell Guide. This includes:
- at least 5 portions of a variety of fruit and vegetables every day
- meals based on starchy carbohydrates such as potatoes, bread, rice and pasta
- some dairy or dairy alternatives (such as soya drinks and yoghurts); choose lower-fat and lower-sugar options
- some beans and pulses, fish, eggs, meat, or other types of protein; aim for 2 portions of fish every week, with 1 being an oily fish, such as salmon or mackerel.
- unsaturated oils and spreads, eaten in small amounts
- plenty of fluids – the government recommends 6 to 8 glasses a day
Young children, especially those under the age of 2, need the concentrated energy provided by fat. There are also some vitamins that are only found in fats.
This is why energy-dense foods such as whole milk, yoghurt, cheese and oily fish are so important.
Once your child is 2, you can gradually introduce lower-fat dairy products and cut down on fat in other foods, as long as your child is a good eater and is growing well.
By the time your child is 5, they should be eating a healthy, low-fat diet like the one recommended for adults.
Foods to be careful about including in your child's diet
- Sugary drinks and foods – it's not recommended to give your child high-sugar drinks and foods. When sugar touches your child's teeth often, and for long periods of time, it causes more damage. If your child does have sugary foods or drinks, it's best to only give them at mealtimes, to minimise damage to their teeth.
- Saturated fats – these are unhealthy fats, such as the type in burgers, sausages, pies, biscuits, cake, and cheese. Try to not give your child these foods often.
- Wholegrain foods – these include foods such as wholemeal pasta, bread and brown rice, which are high in fibre and may make your child feel full before they've taken in the calories and nutrients they need. After the age of 2, you can gradually introduce more wholegrain foods.
Drinks in your child's diet
Water and plain cows' milk are the best drinks for young children after the age of 12 months.
Young children can change from drinking whole (full-fat) milk to semi-skimmed milk after they are 2 years old, but only if they are eating a varied diet and growing well for their age.
If your child is underweight, a doctor or dietitian may recommend they keep drinking whole milk.
Fruit juices are a good source of vitamins and minerals, but they're also high in sugars and acids, which can damage teeth.
If you choose to give your child fruit juices or smoothies, they should be diluted (1 part juice to 10 parts water).
Keep an eye on the amount of fruit juice and smoothies your child has. And remember to keep these to mealtimes only, as they can cause tooth decay.
Make sure your child is not filling up on fluids. Underweight children who are drinking too much fluid and not eating enough do not consume enough calories and miss out on important nutrients.
Find out more about how to eat well.
Vitamins for children
The Department of Health recommends that all children aged between 6 months and 5 years are given vitamin A, C and D drops.
These may be particularly important for underweight children, who may not be eating a diet that is varied enough to provide all the nutrients they need.
You can ask your health visitor where to get vitamin drops or speak to a pharmacist or GP for more advice.
How to increase your child's calorie intake
There are a few steps you can take to increase your child's calorie intake until they reach a healthy weight, while still providing a healthy diet.
- bulk up mashed potato by putting milk or cheese in it
- put grated cheese on beans on toast
- make milk puddings
- make soups with milk instead of water
Food intolerance in children
If your child is unable to eat any lactose (a type of natural sugar in milk and dairy products), for example, the doctor may refer them to a dietitian for tailored nutritional advice.
They can help you ensure that your child gets the right amount of nutrients in their diet for healthy growth and development.
A healthy attitude to food
Children can learn their attitude towards food from the adults around them. The best way to help your child have a lifetime of healthy eating is for them to see you eating a healthy diet and having a healthy attitude towards food.
Make mealtimes family time. Sit around a table and enjoy the food you're eating. It should be a fun and happy part of the day.
Do not associate food with reward or love, as your child will learn to turn to food for comfort instead of when they are hungry.
Introduce a wide variety of foods and tastes early. If your child is a fussy eater, introduce new foods gradually and in small portions.
Offer lots of praise when they eat a new food and ignore negative responses to the food. Be patient – some children need to be offered new foods many times before they will eat them.
Do not insist that a child eats everything on their plate or criticise them when they do not eat as much as you want. This turns mealtimes into a negative experience for your child.
Keep your child active
Even if your child is underweight, it's important that they are physically active.
Physical activity helps them develop strong, healthy bones and muscles. It's an important part of the way they learn about themselves and the world. And, best of all, it's great fun.
If your child is underweight, the amount of physical activity they should do may be different from other children. A GP, practice nurse, school nurse or health visitor can advise on this.
Find out how to get active with your child.
Monitor your child's progress
If you provide a healthy diet using these guidelines and the advice from a GP, you should see your child's weight and growth improve.
Make sure you go back to the GP to check your child's weight gain is happening the way it should.
Once your child is a healthy weight, their diet may need to be adjusted so they do not become overweight.