Weight Management

Weight management is crucial to the long-term health and well-being of people with PWS. Babies with PWS often take food quite poorly. Once this stage is over, if the person does not keep to a lower calorie (energy) diet, they can quickly become very obese and therefore liable to all the conditions which generally accompany obesity, ie:

• heart problems
• breathing problems
• diabetes mellitus
• sleep apnoea (though in PWS, this may be present without significant obesity, due to hypothalmic dysfunction)
• cellulitis
• difficulties in getting around
• low self-esteem

It is common, in those whose diet has not been managed, for people with PWS to reach excessive weights by the time they reach their teens, and in a few individuals this is evident from as young as 4 years old. The life expectancy for people with PWS can be very low - death can occur from obesity-related problems in childhood, teens or early twenties. However, with good weight management, there is no reason why they should not live well into middle age and beyond. The oldest person living with PWS known to the PWSA (UK) is a woman aged 74.

There are two major reasons why obesity is such an issue in PWS and which separate people with PWS from the general obese population:

• Hyperphagia (excessive appetite) - due to hypothalmic dysfunction. It is fairly certain that a message that the person has had enough to eat is not getting through to the brain of the person with PWS. Consequently, the person feels hungry for most of the time. Researchers are currently trying to discover where this "message breakdown" is occurring. To date, appetite suppressants have had no effect on people with PWS, though some limited success has been achieved with some individuals using Orlistat (Xenical) as a treatment. This drug prevents fat from entering the body, but needs careful supervision of diet to avoid side effects such as diarrhoea and staining of underwear.
  
• Low muscle tone and abnormal body composition - this is also probably due to hypothalmic dysfunction, but the cause remains largely unknown. It is evident from birth, but low muscle tone can be improved with growth hormone treatment in children - although this does not address the problem of hyperphagia. The abnormal body composition means that there is more fat and less muscles (ie less lean muscle) in a person with PWS's body than in the body of someone who does not have PWS, but is obese. The person uses up less energy than other people because muscle mass requires more energy to function. The person with PWS therefore needs fewer calories than a person without PWS to maintain a reasonable body weight, and will need fewer calories when dieting than others.

Hence, the person with PWS not only feels hungry for a significantly greater proportion of the time (in some individuals, all the time), but they need less energy (calories) to maintain a reasonable level of weight.

Most people with PWS have some degree of learning disability and behavioural problems which can also impact on how others help them to manage their weight.

All people with PWS vary in their dietary requirements, depending on their BMI (body mass index), degree of exercise, and individual lifestyle. Therefore it is important that they are seen by a registered dietitian, particularly if they wish to lose weight.

MORE INFO ABOUT WEIGHT MANAGEMENT ON THIS SITE:
One parent's use of technology to monitor food-seeking behaviour

NEW PUBLICATION: Healthy Eating and Prader-Willi Syndrome