First of all, it needs to be clear that the three-year-old child is in the period of growth and development, so we can't overemphasize weight loss. If children do have overweight problems, they should take a healthy diet and exercise to control their weight.

Here are some suggestions:

1. Diet: Control children's food intake and avoid overeating. It is recommended to eat more healthy foods such as vegetables, fruits, whole grains, low-fat dairy products and lean meat, and reduce the intake of high-calorie, high-fat and high-sugar foods. At the same time, ensure that children drink enough water every day.

2. Exercise: Encourage children to do proper physical exercise, such as running, swimming and cycling. At least 60 minutes of aerobic exercise every day can help children consume excess calories and enhance their physique.

3. Establish good living habits: work and rest regularly and avoid staying up late; Reduce sedentary time such as watching TV and playing mobile phones; Encourage children to participate in outdoor activities and increase exercise.

4. Parental companionship and guidance: Parents should set an example for their children's healthy lifestyle, participate in sports and diet plans with their children, and give them positive encouragement and support.

It should be noted that extreme methods, such as dieting, overeating and excessive exercise, should not be taken during weight loss, which may have a negative impact on children's health. If your child has a serious weight problem, it is recommended to consult a professional doctor.