Nutrition and Diet in Prader-Willi Syndrome

Nutritional concerns for an individual vary over the lifespan. It is important to assure 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;
  • decrease swallowing;
  • decrease sucking reflexes; and
  • failure to thrive.
Newborns may need to be fed with special soft nipples or with nasogastric or gastrostomy tube feedings up to 6 months of age. They may also need frequent weight checks from visiting nurses or during medical appointments.

Infancy to preschool

Feeding may start to improve around 6 months of age and an insatiable appetite may be seen as early as 12 months of age. Rapid weight gain can lead to life-threatening obesity.
  • Close monitoring is required for those with continued:
    • hypotonia;
    • lethargy and weak suck; or
    • failure to thrive.
  • When children develop insatiable appetites, food intake must be controlled. There is usually a very rapid weight gain even on low caloric diets. Caloric diets (ex. 800 kcal/day) should be adjusted to maintain appropriate weight for height.
  • Supplemental vitamins and calcium should be given.
  • Diets should be well balanced.

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:
  • locking up food (refrigerator, cupboards, or pantries);
  • providing lunches from home (sack lunch or lunch box) since school lunches will be too high in calories;
  • communicating with school and child care personnel about diet restrictions in order to:
    • receive prior notice about school and child care parties involving food or treats;
    • educating school and child care personnel about the need for supervising the child to ensure that food is not taken from other children;
    • adjusting the daily diet to include caloric intake from food and treats from school parties;
    • educating classmates and friends about the disorder and helpful strategies to prevent food trading, stealing, or overeating;
    • using non-food rewards; and
    • restricting caloric intake to 800-1,000 kcal/day.
Other strategies can be used to help improve the child's health by:
  • developing physical activity plans for the family and with the school to help maintain the child's weight and increase the child's tone;
  • providing vitamin and calcium supplements to prevent vitamin deficiencies and osteoporosis; and
  • restricting fluid intake to prevent fluid overload.


This 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 as to the individual's height, from 1,000 to 1200 kcal /day.
  • Adequate calcium and multivitamins must be given.
  • Exercise programs at least 30 min. in length should be a part of every day activities.
  • One-on-one supervision may be needed when in the cafeteria.

Adult years

During these years, parents may be decreasing their role of supervision as the young adult may have the desire to live 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 regarding monitoring and controlling dietary intake.
  • Calories will remain between 1,000-1200 kcal /day. Some may be even be dropped to between 600-800 kcals per day if rapid weight loss is needed. The lower caloric diet may be dependent on their physical activities and the amount of weight gain. Their body mass index (BMI) should always be < 30.
  • 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.


Information & Support

For Professionals

Genetics in Primary Care Institute (AAP)
The goal of this site is to increase collaboration in the care of children with known or suspected genetic disorders. It includes health supervision guidelines and other useful resources; represents a collaboration among the Health Resources & Services Administration, the Maternal and Child Health Bureau, and the American Academy of Pediatrics.


Nutrition Assessment Services

See all Nutrition Assessment Services services providers (3) in our database.

Nutrition, Metabolic

See all Nutrition, Metabolic services providers (2) in our database.

For other services related to this condition, browse our Services categories or search our database.


Author: Judy L. Welch, RN, BSN - 9/2008
Reviewing Author: Kyna Byerly, MS, CGC - 8/2008
Content Last Updated: 2/2015


This page was developed in partnership with the Heartland Genetic Services Collaborative 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.