Prader-Willi Syndrome (PWS)

Prader-Willi syndrome (PWS), a rare and complex neurodevelopmental genetic condition that affects multiple organ systems in the body, causes evolving dietary and nutritional challenges throughout the lives of patients. Although patients need to restrict their diet to avoid excessive weight gain, it is important to ensure adequate consumption of fat, vitamins, and minerals for optimal growth and development. Thus, the management of PWS requires strict dietary planning and supervision, tailored according to the needs of individual patients.^1,2

General Dietary Considerations for PWS

Elimination of Sugar

If possible, sugar should be completely eliminated from the diet of patients, as it does little to curb appetite and can increase the risk of diabetes, which may already be higher for these patients. Reportedly, patient behavior and weight management also improve when sugar is reduced or eliminated from the diet. Children with PWS raised on a sugar-free diet may also be conditioned to make better food choices.²

Read more about PWS risk factors

Optimal Nutritional Intake

It is important to regularly review and follow up on patients’ weight and daily nutritional intake by consulting a dietitian. The caloric intake per day must be restricted for these patients, often to an amount of 50% to 70% of what is typical for that age for children without PWS. Although patients with PWS need to follow a highly restricted low-calorie, low-carbohydrate diet, it should be well balanced, containing a variety of high-quality, nutrient-rich foods (such as fruits, vegetables, proteins, dairy, and good fats).^2,3

An approximate recommended diet for patients with PWS contains 40% complex carbohydrates, 30% protein, and 30% healthy fats, with a focus on nonstarchy vegetables, fiber, and high-quality protein, with strict avoidance of processed foods and sweet drinks. To monitor the intake of macronutrients, patients can stick to simple foods with few ingredients.^2,3

Read more about PWS treatment

Regular Exercise

It is important for patients with PWS to exercise regularly for at least 30 minutes each day. The amount of exercise should be increased if the patient is overweight.²

Removal of Temptation

Patients with PWS may benefit from rules and routines related to food, such as eating only at the table, eating a predictable menu, or eating meals at predictable times. It is in the patients’ best interests that neither their tantrums are given into nor are they rewarded with food. Keeping the food “secure,” ie, keeping the food locked in the kitchen, fridge, pantry, or other food storage at all times except meal times or snack breaks, can help manage weight and patient behavior by reducing the temptation to eat, tantrums when food is denied, and feelings of guilt or failure to control themselves. Continuous supervision of patients with PWS can help control hyperphagia.^2,3

Patient Education

Educating patients with PWS about nutrition and the harmful effects of junk food and overeating on the body can help them manage their excessive appetite.²

Dietary Considerations for PWS by Age

Neonates

Neonates with poor sucking reflex and feeding challenges may need tube feedings or assistance with special nipples. In addition, frequent weight monitoring may be required to maintain healthy body weight.⁴

Read more about PWS guidelines

Infancy to Preschool

Feeding challenges may start to improve around 6 months of age. However, appetite may increase abnormally as early as 12 months of age, which may lead to excessive eating that must be controlled. If left unmanaged, it can lead to rapid weight gain and life-threatening obesity. Growth, including height and weight, must be monitored using PWS-specific standardized growth charts. Children should be given multivitamin and calcium supplements along with a well-balanced diet.⁴

School Age

As children with PWS enter school, they experience social and behavioral difficulties. Excessive eating may be controlled by providing a food-secure environment, which may be achieved by locking cupboards or refrigerators, providing homemade lunches instead of school lunches, educating school personnel about dietary restrictions, informing friends and classmates about PWS, and implementing other strategies to prevent food stealing or overeating.⁴ 

Other strategies to improve the health of children with PWS include restricting the caloric intake (usually to 800 to 1000 kcal per day), developing physical activity plans with their family and school, giving vitamin, iron, and calcium supplements to prevent deficiencies and osteoporosis, and monitoring growth using standardized PWS-specific growth charts.⁴

Read more about PWS complications

Adolescence

Adolescence is the age when an individual undergoes body changes, becomes aware of differences between individuals, and often becomes conscious about the body. Caloric intake should be restricted to around 1000 to 1200 kcal per day, adjusted according to the individual’s height. However, it may be difficult to control their diet at social gatherings. Multivitamin, iron, and calcium supplements should be given, and patients should exercise for at least 30 minutes per day. A visit to a restaurant or cafe must be supervised. Growth, including weight and height, can be monitored using PWS-specific standardized growth charts.^4,5

Adults

Patients with PWS who reach adulthood become more independent and may be able to work. Thus, it is important to monitor their weight frequently and educate their supervisors about controlling dietary intake, which may depend on the amount of physical activity and their weight. Caloric intake can vary from 1000 to 1200 kcal per day, however, it may be reduced to 600 to 800 kcal per day if weight needs to be reduced. Adults may continue to need multivitamin and calcium supplements.⁴ 

Read more about PWS prognosis

References

1. Driscoll DJ, Miller JL, Cassidy SB. Prader-Willi syndrome. In: Adam MP, Mirzaa GM, Pagon RA, et al, eds. GeneReviews^® [Internet]. Seattle, WA: University of Washington, Seattle; 2023. October 6, 1998. Updated March 9, 2023. Accessed August 1, 2023.
2. Dietary management. Prader-Willi Syndrome Association New Zealand. Accessed August 1, 2023.
3. Diet and nutrition for adults. Prader-Willi Syndrome Association Victoria. Accessed August 1, 2023.
4. Butler MG. Prader-Willi syndrome nutrition & diet. Medical Home Portal. September 2008. Updated July 2019. Accessed August 1, 2023.
5. Miller JL, Tan M. Dietary management for adolescents with Prader-Willi syndrome. Adolesc Health Med Ther. 2020;11:113-118. doi:10.2147/AHMT.S214893

Reviewed by Hasan Avcu, MD, on 8/4/2023.

---

Erum Naqvi, PhD

Erum Naqvi obtained her Ph.D. in Molecular Medicine from Hannover Medical School (Germany) after completing her Masters in Biomedical Science and Bachelors in Microbiology from University of Delhi (India). She has several years of experience as a science writer.