Overweight children and their families will attend free 10-week health courses as part of a campaign to tackle childhood obesity.
The £1.4 million scheme will target about 2,000 seven to 13-year-olds in Wales over the next three years.
It comes the week after an NHS dietician revealed children as young as two were being treated for obesity.
Families will get advice on healthy eating, physical activity and shopping on a budget after enrolling themselves or being referred by a GP.
Professionals will be on hand to help change behaviour and build children's confidence. Follow-up sessions and telephone support will be available to those who attend.
Rather than focus on losing weight, the Welsh Assembly Government said the twice-weekly classes will teach "weight management skills".
The Mend programme - short for Mind, Exercise, Nutrition ... Do It! - was devised by child health experts at Great Ormond Street Hospital and University College London.
Pilot schemes have been running in four parts of Wales since last September. Families taking part in a trial lost an average 4.3cm (1.7ins) from their waists after six months.
About one in five 13-year-olds in Wales is said to be obese or overweight.Reuse content