This randomized trial aims to evaluate the health-promoting effects of intermittent dietary restrictions, including intermittent low-carbohydrate diet (ILCD) and calorie restriction (ICR), in school-aged children with cardiometabolic risk (CMR) compared with general health education based on dietary and physical activity guidelines for Chinese children.

Childhood obesity comorbid with one or more CMR factors, including hyperglycemia, dyslipidemia, and hypertension, predicts an increased risk for developing cardiovascular disease in adulthood. Lifestyle interventions, including restricting dietary calorie intake and increasing physical activity, have been proposed as the first-line behavioral weight management approaches for pediatric obesity. Long-term adherence to daily dietary restriction is challenging for young populations because they are in a particular period of physical and psychological growth and lifestyle formation. Low-carbohydrate diet and ICR have shown effectiveness in improving cardiometabolic health in adults, however, the evidence supporting the effects of these diets in pediatric populations remains limited.

Eligible participants will be randomized to receive intermittent dietary restriction, including an ILCD (carbohydrate intake ≤ 50 g/d for two days per week) or an ICR (calorie intake is 500-600 kcal/d for two days per week), or general health education based on dietary and physical activity guidelines for Chinese children in daily life. The total study duration will be 12 months consisting of a 3-month intervention phase and a 9-month self-maintenance phase.

Inclusion Criteria:

• Aged 7-18 years at baseline.

• At least one of the following cardio-metabolic abnormalities:

  1. Prediabetes (Impaired fasting glucose: 5.6 ≤ fasting blood glucose level ≤ 6.9 mmol/L; or Impaired glucose tolerance: 7.8 ≤ blood glucose level after 2 hours postprandial ≤ 11.0 mmol/L).
  2. Lipid abnormalities (High-density lipoprotein cholesterol ≤ 1.04 mmol/L; or Low-density lipoprotein cholesterol ≥ 3.37 mmol/L; or Triglycerides ≥ 1.70 mmol/L, or Total cholesterol ≥ 5.18 mmol/L).
  3. Elevated blood pressure (Systolic/diastolic blood pressure consistently higher than the 90th percentile for gender, age, and height; or systolic/diastolic blood pressure ≥ 120/80 mmHg).

Exclusion Criteria:

• Previously diagnosed with heart failure, severe malnutrition, immune deficiency, liver or kidney disease, cancer, or other diseases deemed unsuitable for participation.
• Had a history of bariatric surgery.
• Used weight loss pills or supplements in the last three months.
• Other situations unsuitable for participation.