She is calling on parents to jump in and help, by preparing healthy school lunch boxes for their children and to be aware of the importance of making good choices.

According to Kruger, physical activity should be made part of the school curriculum, and extra fun sport activities should be organized for children who do not make the team. She said more nutrition information in the school curriculum could also add value.

Kruger said one of the main problems lay with school tuck-shops and vendors sitting at the school gates with their unhealthy offerings.“Tuck-shops often sell fizzy cold drinks, sweets, biscuits and crisps. These are high in either sugars, refined starch or salt and fat,” she said.

“They are sources of energy, but in our context of undernutrition when it comes to vitamins and minerals, such as iron, these foods do not make a contribution to feed a growing child.”

Vendors at school gates sell similar foods, although they sometimes offer healthier alternatives such as chicken feet, fresh fruit or sandwiches.“Efforts should be made to sell milk, milk drinks, yogurt, maas and fresh fruit in tuck-shops,” she said.

According to Kruger children need to eat more frequently than adults, due to their smaller gastric capacity and relatively greater need for nutrients such as iron and calcium in foods to sustain growth.

“It is necessary to focus on nutrients for growth and development, such as protein, calcium, iron and zinc and vitamins for immune function,” said Kruger.

She believes parents should prepare protein foods for lunch boxes. These would include eggs, cheese, nuts, peanut-butter, biltong and cold meats, salads with beans or lentils. Milk (fresh or flavoured) and yogurt are also good sources of protein, calcium and B-vitamins.

“Eating fresh vegetables and fruits instead of drinking fruit juice leads to greater satiety, generally combined with a lower sugar intake,” Kruger said.

She explained that whole-wheat bread and crackers for sandwiches could be alternated with muffins or oat cookies as a source of energy and B-vitamins.

General information on eating and appetite to prevent excessive weight gain

Balanced diets contain whole foods, such as proteins (meat, eggs, legumes, milk), fruits and vegetables, whole-grain starchy foods and small amounts of added fats and oils plus water.

Whole fruits contain fibre, making it necessary for them to be chewed before swallowing. Chewing causes the fruit to be absorbed over a longer time than juice does, and sends a message to the brain that food has been eaten and there is now a feeling of fullness

The soluble fibre in fruits, vegetables and legumes (beans, peas and lentils) also helps to regulate blood sugar after food intake. Less fluctuation in blood glucose after meals also helps to curb the appetite. Fruit also contains less calories than juice. For example a large orange will provide 340 kJ of energy, while a glass of orange juice, usually sweetened, contains about 440kJ.

Over a period of time this difference in kJ will make a significant difference in a person’s overall energy intake and weight balance. Highly processed foods are easy to ingest, require minimal chewing and are also generally more energy dense, containing more kJ and fat.