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.
The GP will weigh and measure your child and talk to you about what your child is eating. If there is a possible 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 dietitan.
Paediatric dietitian Jacqui Lowden, from the Manchester Children's Hospital, says a varied diet will see most underweight children achieve a healthy weight.
What your child needs
All children need the energy (calories) and nutrients that come from a varied and balanced diet.
"Remember, children have smaller stomachs," says Jacqui. "They may not get all the energy they need from three meals a day, and may need to eat some small snacks to boost their energy intake.
"They 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.
A balanced diet for a young child means having a variety of foods from the four main food groups:
- meals based on starchy carbohydrates, such as bread, pasta, rice or potatoes
- your child should eat a variety of fruit and vegetables a day – for ideas, see 5 A DAY and your family
- give your child protein from meat, fish, eggs, beans, pulses and other non-dairy sources
- include some milk and dairy foods in your child's diet, such as cheese and yoghurt – these are great sources of protein and calcium
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 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 – so that by the time your child is five, they are eating a healthy low-fat diet like the one recommended for adults. Find out more in What to feed young children.
Don't let your child sip sugary drinks and eat sugary foods too often. 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.
Drinks in your child's diet
Water or plain cow's 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. Sugary drinks provide calories, but shouldn't be given to babies and toddlers as they can cause tooth decay.
Fruit juices are a good source of vitamin C, but they also contain natural sugars and acids, which can damage teeth. Diluted fruit juice (one part juice to 10 parts water) can be given to children with their meals after six months.
Find out more about the different food groups and how they form part of a balanced diet.
A child's diet
It's important to remember, says Jacqui, that 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.
Young children need the concentrated energy provided by fat in their diet. But give them healthy, energy-dense foods such as oily fish, milk, yoghurt and cheese. Limit saturated fats such as those contained in burgers, sausages, pies, biscuits and cake.
"Up to two years old, all children should drink whole [full-fat] milk," says Jacqui. "If your child is underweight, you can continue to give them full-fat milk beyond this."
Children can have whole cow's milk as a drink after one year, and semi-skimmed cow's milk can be introduced after two years. But if your child is underweight, it may be important to continue giving your child whole milk after two years.
Young children shouldn't follow a high-fibre diet. Wholegrain foods such as wholemeal pasta, bread and brown rice may fill up your child too quickly, which means they won't get all the calories they need. Introduce wholegrain foods gradually so that by the time children are five, they are used to a healthy adult diet.
Make sure your child is not filling up on fluids. "We see some children who are drinking too much fluid and not eating enough, which means they don't consume enough calories and important nutrients," says Jacqui.
Increasing 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 for a great balanced pudding
- make soups with milk instead of water
- use other energy-dense foods such as bananas and avocado in meals or as snacks between meals
Food intolerance in children
If you think your child may be intolerant to a particular food or has a food allergy, it is important to talk to your doctor to determine exactly what may be causing their symptoms.
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.
See how cooking with your child can help you introduce healthy foods into their 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.
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 a crucial 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. You can check their weight with the healthy weight calculator.