If you're concerned that your child is underweight or not growing normally, see your GP. Low weight can occur for a number of reasons.
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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 healthy weight calculator.
If your child is in Reception (ages four and five), 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, consult your GP, who can talk to you about the possible causes.
If there is a problem with your child's diet, your GP can provide advice that will help bring your child up 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 that for an adult. Many of the "healthier alternatives" that adults are advised to eat aren't suitable for toddlers and very young children.
Children have smaller stomachs than adults and need to eat smaller amounts more frequently. Three meals a day with three smaller snacks at regular intervals is typical.
If your child is underweight, it might be tempting to give them high-calorie but unhealthy foods, such as sweets, chocolate, cakes, sugary drinks and fatty foods and drinks. But a varied, balanced diet is the key to your child's healthy weight gain.
What is a balanced diet?
A balanced diet for a young child means having a variety of foods, following the Eatwell Guide. From the age of two a child should be moving towards a diet that is similar to the rest of the family, in line with the Eatwell Guide:
- At least five portions of a variety of fruit and vegetables every day.
- Meals based on potatoes, bread, rice, pasta or other starchy carbohydrates.
- 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 and other protein. Aim for two portions of fish every week - one of which should be oily, such as salmon or mackerel.
- Unsaturated oils and spreads - eat in small amounts.
- Plenty of fluids - the government recommends 6-8 cups/glasses a day.
Young children, especially those under the age of two, 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 two, you can gradually introduce lower-fat dairy products and cut down on fat in other foods - providing your child is a good eater and is growing well.
By the time your child is five, they should be eating a healthy low-fat diet like the one recommended for adults.
Find out more in What to feed young children.
What to watch in your child's diet
- Sugary drinks and foods - it's not recommended to give your child high sugar drinks and foods. The longer and more often sugar touches your child's teeth, the more damage it causes. If your child does have sugary foods or drinks, it's best to give them at mealtimes to minimise damage to their teeth.
- Saturated fats - these are unhealthy fats, such as those contained in burgers, sausages, pies, biscuits, cake and cheese. Try not to give these too often.
- Wholegrains - wholegrain foods, such as wholemeal pasta, bread and brown rice, can be high in fibre and may fill up your child before they've taken in the calories and nutrients they need. After the age of two, you can gradually introduce more wholegrain foods.
Drinks in your child's diet
Water or plain cows' milk are the best drinks for young children after the age of 12 months.
Young children can move from having whole (full-fat) milk to semi-skimmed milk once they are two years old, but only if they are having a varied diet and are growing well for their age.
If your child is underweight, your doctor or dietitian may recommend they carry on having 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 juice or smoothies, these should be diluted (one 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, 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 don't consume enough calories and miss out on important nutrients.
Find out more about the different food groups and how they form part of a balanced diet.
Vitamins for children
The Department of Health recommends that all children aged between six months and five 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 your 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 tolerate any lactose (a type of sugar found in milk and dairy products), for example, your 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 set up your child for a lifetime of healthy eating is to let them see you eating a healthy diet and having a healthy attitude towards food.
Make mealtime family time. Sit around a table and enjoy the food you're eating. It should be a fun and happy part of the day.
Don't 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.
Don't insist that a child eats everything on their plate or criticise them when they don't eat as much as you want. This turns mealtimes into a negative experience for the 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. Your 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 coupled with advice from your GP, you should see your child's weight and growth improve.
Make sure you go back to your 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 adjusting so they do not become overweight.
Article provided by NHS Choices