No single “best” diet
The RESIST study did not show better outcomes from the increased-protein diet compared with the higher-carbohydrate diet.
Prediabetes in Children & Adolescents
Structured nutrition can be useful for adolescents with prediabetes, but the evidence does not support one rigid “high-protein” or “high-carbohydrate” diet for every teenager. Current care focuses on an individualized, family-centered eating pattern, regular physical activity, healthy growth and careful medical follow-up.
The RESIST study did not show better outcomes from the increased-protein diet compared with the higher-carbohydrate diet.
Food choices need to fit the adolescent's culture, family habits, budget, growth needs and risk of disordered eating.
Nutrition, regular physical activity, sleep, weight management when appropriate, and medical follow-up should be considered together.
The original page was based on the Australian RESIST trial—Researching Effective Strategies to Improve Insulin Sensitivity in Children and Teenagers. It was a randomized controlled trial conducted at two hospitals in Sydney.
The adolescents improved in several measures during the intervention. Insulin sensitivity improved and body-size measures decreased. In the later 12-month report, body fat also decreased among participants who completed the program.
That means the study should not be interpreted as evidence that adolescents with prediabetes should automatically be placed on a high-protein diet. A more reasonable interpretation is that a structured, supervised lifestyle program can be useful, while the exact macronutrient pattern needs to be individualized.
Current American Diabetes Association guidance recommends individualized medical nutrition therapy for children and adolescents with prediabetes or diabetes. The emphasis is on more nonstarchy vegetables, whole fruits, legumes, whole grains, nuts and seeds, and fewer sugar-sweetened beverages, sweets, refined grains and highly processed foods.
In children and teenagers, I am particularly careful about rigid or highly restrictive diets. Nutrition must support normal growth, puberty, bone health, school performance and a healthy relationship with food.
The eating plan should also be realistic for the family. Cost, cultural food preferences, meal schedules, access to healthy foods and the adolescent's willingness to follow the plan all matter.
Not routinely. A teenager may eat an appropriate amount of protein as part of a balanced eating pattern, but the RESIST trial did not establish a special advantage from increasing protein at the expense of carbohydrate.
I would focus much more on the quality of the overall diet: reducing sugary drinks and heavily processed foods, improving fiber intake, choosing minimally processed carbohydrate sources, including appropriate protein foods, and building meals the family can maintain.
Learn more about food choices and blood sugar.
Prediabetes does not mean that a growing teenager must eliminate carbohydrates. Carbohydrate-containing foods differ greatly in nutritional quality. Whole fruits, beans, lentils, vegetables, intact whole grains and dairy foods are very different from sugary drinks, sweets and highly refined snacks.
The amount and distribution of carbohydrate may still need adjustment for an individual child, especially when glucose levels are abnormal, but this should be done with attention to total energy intake, growth and nutritional adequacy.
Current ADA guidance recommends that children and adolescents, including those with prediabetes and diabetes, work toward about 60 minutes of moderate-to-vigorous physical activity each day, with vigorous muscle- and bone-strengthening activity on at least three days per week.
This does not mean a previously inactive teenager should suddenly begin an intense exercise program. The plan should be age-appropriate, enjoyable and realistic, and medical advice may be needed when there are other health conditions.
No. Prediabetes in young people deserves attention, but it is not identical to prediabetes in adults. Puberty itself temporarily increases insulin resistance, and some adolescents return to normal glucose regulation as insulin sensitivity improves.
International pediatric guidance also notes that the usual prediabetes thresholds were largely derived from adult data rather than specifically validated in young people. This is one reason an isolated HbA1c or glucose result should be interpreted in the full clinical context.
The ADA allows fasting plasma glucose, HbA1c and the 2-hour glucose value during an oral glucose tolerance test to be used when evaluating children and adolescents for prediabetes or type 2 diabetes.
| Test | ADA prediabetes range |
|---|---|
| Fasting plasma glucose | 100–125 mg/dL (5.6–6.9 mmol/L) |
| 2-hour glucose during OGTT | 140–199 mg/dL (7.8–11.0 mmol/L) |
| HbA1c | 5.7–6.4% (39–47 mmol/mol) |
Screening is generally considered after the onset of puberty or after age 10, whichever comes first, in children with overweight or obesity who also have additional diabetes risk factors.
If type 2 diabetes is suspected in a child or adolescent with hyperglycemia, clinicians may also test pancreatic autoantibodies because type 1 and type 2 diabetes can overlap in presentation.
Learn more about blood tests for diabetes and insulin resistance.
This is another area where the original article needs an important clarification. Every participant in RESIST received metformin, but that study design does not mean that every adolescent with prediabetes should take metformin.
Current ISPAD pediatric guidance states that there are insufficient data to support metformin, GLP-1 receptor agonists or insulin specifically for the purpose of preventing progression from prediabetes to type 2 diabetes in youth.
That is different from diagnosed type 2 diabetes. In young people with established type 2 diabetes, metformin and other medications may be appropriate depending on glucose levels, symptoms and the clinical situation.
When a teenager has prediabetes, I would not begin by asking, “Which strict diet should we put this child on?” I would first confirm what the glucose results really show, look at growth and puberty, family history, weight trajectory, blood pressure, lipids, liver health, physical activity, sleep and the family's usual food pattern.
Then I would build a plan that the adolescent and family can actually live with. A teenager needs nutrition for growth, not an adult crash diet. The goal is to improve metabolic health while protecting normal development and the young person's relationship with food.
Specialist assessment is particularly useful when glucose or HbA1c continues to rise, the diagnosis is uncertain, there are symptoms of diabetes, severe obesity or rapid weight change, marked insulin-resistance signs such as acanthosis nigricans, PCOS, fatty liver disease, or a strong family history of early-onset type 2 diabetes.
A child or teenager with excessive thirst, frequent urination, unexplained weight loss, vomiting, abdominal pain, unusual sleepiness or deep/rapid breathing needs prompt medical evaluation. These symptoms can occur with significant hyperglycemia and, in some cases, diabetic ketoacidosis.
Some adolescents return to normal glucose regulation, particularly when risk factors improve and pubertal insulin resistance decreases. Continued follow-up is still important because risk varies from one young person to another.
Not automatically. Current pediatric guidance emphasizes individualized, nutritionally adequate eating rather than one mandatory carbohydrate percentage.
Family involvement is usually helpful because shopping, cooking, meal timing and activity habits are shared within the household.
HbA1c can be used, but pediatric prediabetes is more complex than simply applying an adult cutoff. Fasting glucose, OGTT results and the clinical context may also be important.