The worry is they could be missing out on the protein, fibre, fat, vitamins and minerals they need to grow and thrive.
According to the National Diet and Nutrition Survey,i only eight per cent of boys and nine per cent of girls aged 11 to 18 are getting at least five portions of fruit and vegetables a day.
Here are 10 simple, healthy foods that can be easily added to your children's diets:
1. Sweet potato
Not only is sweet potato healthy and filling, but it can also be adapted to multiple dishes – mashed, roasted or turned into healthy oven-cooked chips coated with low fat spray.
It tastes sweet compared to other starchy foods, making it more appealing to kids – and it's also high in vitamin C needed for a healthy immune system and growing.ii Other ingredients include vitamin A for eye health, B1, B2 and B6 for releasing energy, as well as manganese, potassium and fibre.iii Its lower glycaemic index value means that it releases energy slowly and prevents blood sugar spikes.
The high antioxidant content of blueberries make them a great choice as one of your child's five-a-day. Blueberries contain vitamins C, vitamins A and K, fibre and manganese.iv Mix with natural yoghurt for a delicious pudding or a breakfast topping with cereal.
Salmon is an excellent source of vitamin D needed for healthy bones and omega 3 fatty acids which supports brain development (take care to remove bones though). Omega 3s have also recently been found to help improve a child's ability to read.
Avocado is the star of Instagram and it's also packed full of important nutrients and healthy fat. It's rich in vitamin E, which promotes healthy skin and hair, and is one of the only fruits high in monosaturated fats, which maintain good heart health.vii
Yogurt is high in calcium for healthy bones and teeth, protein for tissue repair and vitamin B12 – needed for a healthy nervous system. Try chopping up some of your children's favourite fruit and mix it into natural or Greek yogurt rather than buy sugary yoghurts.
6. Cherry tomatoes
These are the cute, miniature tomatoes that work wonderfully chopped up in salads and sandwiches, or on their own as a healthy snack. They're easy to eat, and fit into lunch boxes with less mess than large tomatoes. They're high in antioxidants, viii fibre and vitamin C.ix
For younger children, be sure to chop them up into smaller pieces to avoid choking.
7. Cream cheese triangles
Cheese triangles are a convenient snack to pop in the lunch box, providing a boost of calcium for healthy bones and teeth and protein for building and repairing tissue. Spread them on oatcakes or wholemeal pitta bread as a healthy snack.x Check the salt content though, as some brands contain higher sodium levels than others, they are usually less salty than cheddar cheese though. Limit them to no more than one a day.xi
8. Wholegrain bread
Toast and sandwiches made with wholegrain bread are great for breakfasts and lunch boxes. Wholegrains contain fibre to regulate blood sugar and maintain healthy digestion and B vitamins to release energy from foods.xxi
One of the big advantages of eggs, is that they're unbelievably versatile. Fried, boiled, poached, scrambled and eaten as omelette; there's a never-ending list of how you can prepare them. They're a great source of protein, helping young bodies grow, as well as being high in vitamin D, vitamin B12, selenium and choline. xiii
Eating up their greens is a golden rule for children and broccoli is high in fibre, potassium, and vitamins C, K, A and B6. xiv Vitamin C is needed for a healthy immune system and helps the body absorb iron. Vitamin A is important for eye health and healthy skin. xv
Supplements for extra support
Fussy eaters can miss out on the vitamins and minerals they need. While you shouldn't give up on offering a variety of foods, a multivitamin supplement can give them a safety net.
For younger children, the Department of Health recommends those aged six months to five years are given daily multivitamins that contain vitamins A, C and D. xvi Everyone aged one and over is recommended to take a 10mcg a day vitamin D supplement in autumn and winter.