Most experts recommend the “slowly-slowly-catchy-monkey” approach. Introduce changes gently — not all at the same time — but firmly. Here’s how:

1 It starts in the supermarket, says Merlin. “What you put in your trolley will end up in your child’s stomach.”

2 Educate carers about nutrition and be clear about how you want your children fed when you’re not around. Make a point of knowing what your child has eaten while you’ve been at work.

3 Educate your children about nutrition. Research findings suggest that children are more likely to eat a healthy diet if they understand the benefits, but they need direct messages from parents and teachers to motivate them to change their eating habits. Marketos also suggests talking to your children about how advertising can affect them.

4 Set an example. Eat fruit, dried fruit and nuts as snacks, avoid refined carbohydrates, drink water. Cari Corbet-Owen, a clinical psychologist who specialises in eating disorders and author of Mind Over Fatter: How to ‘Fat-Proof’ Your Child (Oshun), says: “You are your children’s most important role model. Your attitudes towards food are the single most important factor in determining what they’ll eat.”

5 Serve healthy meals at the table on a regular basis. Don’t eat in front of the television.

6 Don’t ban treats and create the “forbidden fruit” syndrome, says Cawood. Instead, educate your child and maintain firm boundaries and rules, for example, giving treats only on Saturdays or Sundays, or one small treat after dinner.

7 Be firm. Don’t get wobbly in the face of dissent. “Parents have gone too far towards the permissive end of the parenting continuum. In their genuine efforts to move away from autocratic parenting, they have become inconsistent, and they waver between the two extremes: on the one hand being soft and allowing their children to make their own choices and then, when they cannot take the repercussions of this inconsistency, they become harsh and punitive,” says Cawood. Merlin agrees: “Be strong. It’s a cliche, but sometimes you have to be cruel to be kind.”

8 Allow your children some choice, but with parameters. “Should we have macaroni and salad, or cottage pie and peas ” If they want neither, make it clear that there are no other choices.

9 If your child refuses to eat what is put before him, don’t make a fuss, but don’t allow him to eat anything other than fruit instead. “Children learn to manipulate their parents, because the parent feels so guilty if the child has not eaten. They’re inclined then to give the child what he/she wants just so that they have something in their stomach before they go to bed. This sets the scene for huge power struggles over food,” says Cawood.