Prader-Willi Syndrome Nutrition & Diet

Individuals with Prader-Willi syndrome (PWS) will face evolving nutritional issues throughout their lives. It is important to ensure adequate dietary fat for brain growth and development while preventing excessive weight gain.

Newborn period

Newborns may have marked hypotonia leading to:

  • Poor arousal
  • Poor interest in eating
  • Decreased swallowing
  • Decreased sucking reflexes
  • Failure to thrive
Newborns may need to be fed with special soft nipples or nasogastric or gastrostomy tube feedings until they are 6 months old. They also may need frequent weight checks at medical appointments or home from visiting nurses.

Infancy to preschool

Feeding issues may start to improve when the infant is about 6 months old. An insatiable appetite may be seen as early as 12 months old. When children develop insatiable appetites, food intake must be controlled. Usually, a very rapid weight gain occurs, even with low-calorie diets. Caloric diets (>800 kcal/day) should be adjusted to maintain appropriate weight for height. Rapid weight gain can lead to life-threatening obesity.

  • Give supplemental vitamins and calcium.
  • Maintain a well-balanced diet.
  • Use PWS-specific standardized growth charts to monitor growth and acceleration, including weight and height. These can be found at [Butler: 2011].

Closely monitor those with continued:

  • Hypotonia
  • Lethargy and weak suck
  • Failure to thrive

School age

In addition to weight control, behavioral and social challenges occur as children enter school. Uncontrolled eating leading to morbid obesity may be controlled by a food-secure environment:

  • Lock up food (refrigerator, cupboards, or pantries).
  • Provide lunches from home (sack lunch or lunch box) since school lunches will be too high in calories.
  • Communicate with the school and childcare personnel about diet restrictions in order to:
    • Receive prior notice about school and childcare parties involving food or treats.
    • Educate school and childcare personnel about the need for supervising the child to ensure that food is not taken from other children.
    • Adjust the daily diet to include caloric intake from food and treats from school parties.
    • Educate classmates and friends about the disorder and helpful strategies to prevent food trading, stealing, or overeating.
    • Use non-food rewards.
    • Restrict caloric intake to 800-1,000 kcal/day.
Other strategies can help improve the child's health:
  • Develop physical activity plans for the family and with the school to help maintain the child's weight and increase the child's muscle tone.
  • Provide vitamin and calcium supplements to prevent vitamin deficiencies and osteoporosis.
  • Restrict fluid intake to prevent fluid overload.
  • Use PWS-specific, standardized growth charts to monitor growth and acceleration, including weight and height. These can be found at [Butler: 2015] and [Butler: 2016].


Adolescence is a time of body changes and awareness of differences between individuals. There is a strong need for the child to maintain a reasonable weight. Food sharing and activities where food is present will increase the frustration of being on a controlled diet and stealing food may increase.

  • Caloric restrictions need to be adjusted for the individual's height from 1,000 to 1,200 kcal/day.
  • Adequate calcium and multivitamins must be given.
  • Exercise programs, at least 30 minutes in length, should be a part of everyday activities.
  • One-on-one supervision may be needed when in the cafeteria.
  • Use PWS-specific, standardized growth charts to monitor growth and acceleration, including weight and height. These can be found at [Butler: 2015] and [Butler: 2016].

Adult years

Parents of an individual with Prader-Willi syndrome may be decreasing their role of supervision as the young adult begins to want to live more independently and work in vocational settings. Although adults with PWS do not live on their own, they may be living in group homes. They may begin to use public transportation, and this will offer opportunities for them to buy or steal food. New supervisors may need to be educated about monitoring and controlling dietary intake.

Calories will remain between 1,000-1,200 kcal/day. Some diets may include 600-800 kcals per day if rapid weight loss is needed. The lower calorie diet may be dependent on physical activity level and the amount of weight gain. A goal for body mass index (BMI) might be to maintain at <30 for adults depending on the status of the individual with PWS. Calcium and multivitamin supplements must be given to prevent further osteoporosis. Frequent weight checks are necessary during this new time of independence and change of supervision.


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Authors & Reviewers

Initial publication: September 2008; last update/revision: July 2019
Current Authors and Reviewers:
Author: Merlin G. Butler, MD, PhD
Funding: This page was developed in partnership with the Heartland Genetic Services Network and was funded in part by a Health Resources Services Administration (HRSA) cooperative agreement (U22MC03962). We appreciate the Prader-Willi Syndrome Association (USA) for their outstanding support of individuals with PWS and their families and for the information they provide on their website – – to which we have provided several links within the Diagnosis Module.
Authoring history
2008: update: Judy L. Welch, RN, BSNA
2008: first version: Kyna Byerly, MS, CGCCA
AAuthor; CAContributing Author; SASenior Author; RReviewer

Page Bibliography

Butler MG, Lee J, Cox DM, Manzardo AM, Gold JA, Miller JL, Roof E, Dykens E, Kimonis V, Driscoll DJ.
Growth Charts for Prader-Willi Syndrome During Growth Hormone Treatment.
Clin Pediatr (Phila). 2016;55(10):957-74. PubMed abstract / Full Text

Butler MG, Lee J, Manzardo AM, Gold JA, Miller JL, Kimonis V, Driscoll DJ.
Growth charts for non-growth hormone treated prader-willi syndrome.
Pediatrics. 2015;135(1):e126-35. PubMed abstract / Full Text

Butler MG, Sturich J, Lee J, Myers SE, Whitman BY, Gold J, Kimonis V, Scheimann A, Terrazas N, Driscoll DJ. .
Growth Standards in Infants with Prader-Willi Syndrome.
Pediatrics. 2011;In press( Vol. 127 ):No. 4 April 1, 2011 . / Full Text
Standardized growth curves for weight, length, head circumference, weight/length, and BMI for non–growth hormone–treated white infants (boys and girls) with Prader-Willi syndrome (PWS) between 0 and 36 months of age.