Understanding the Diet

by Linda Thornton

In Prader-Willi syndrome, because there is a dysfunction in the hypothalamus, the brain tells the body it is starving - it must eat. To a person with PWS, eating becomes the only means of survival and everything is directed towards this. So, knowing how to manage this is imperative.

There is no choice where food is concerned. It is as though there is no "on/off" switch, so it is critical to get the balance right. Without suport and good management, the end result will be morbid obesity. Having an insatiable appetite with no ability to control the urge to eat means that without supervision and monitoring, the person with PWS will eat continuously which will undoubtedly compromise health, and result in death.

This is a syndrome that cannot be cured or changed by behavioural intervention, but it can be managed. Early growth hormone treatment for children can be a great help in keeping the balance between diet and exercise.

A person with PWS (with, or without GHT) can not be expected to make good food choices for themselves. They will try to convince you to break their dietary guidelines. You must assist them to try to keep to the rules around food. This, in effect, means good menu planning.

Decide what calorie level the person needs - the rule of thumb is 1,000 calories (4,000 kilojules) per day, will help lose weight. With PWS, and with the guidance of a dietician, some adult diets will go as low as 800 cals (3,200 kilojules), but do not undertake this without guidance. And, of course, it is a different matter for children.

Having worked out the calorie level needed, prepare food ahead of time, making sure that what you say is on the menu is what they receive. If you deviate from the agreed caloric amount, the end result will be weight gain.

The Importance of Exercise

The imbalance in PWS of low growth hormone production combined with low muscle tone means exercise will be more difficult for children and adults. The decreased quantity of muscle tissue (causing low muscle tone) accounts for the difference in energy expenditure (ability to exercise). Having growth hormone treatment will increase muscle tone and therefore increase the ability to exercise and burn off calories. Not having access to GHT means the person with PWS will have to work even harder to burn off calories.

And not many people with PWS really like to exercise... and sometimes it's best to not even use that word! There is much to be said for "hidden" exercise, particularly doing things they like to do.

Know what exercise burns calories

For example, a person weighing 90-99 kg

  • Swimming for 30 minutes will burn 360 calories (1440kj)
  • Walking steadily for 30 mins will burn 246 calories (984 kj)
  • Lawnmowing for 30 mins will burn 318 calories (1272kj)
  • Vacuuming for 30 mins will burn 186 calories (744kj)
  • Dancing (easy aerobics) for 30 mins will burn 282 cals (1128kj)

For a person weighing 80-89 kg

  • Swimming for 30 minutes will burn 324 cals (1296kj)
  • Walking for 30 mins will burn 234 cals (936kj)
  • Lawnmowing for 30 mins will burn 285 cals (1140kj)
  • Vacuuming for 30 mins will burn 165 cals (660kj)
  • Dancing (easy aerobics) for 30 mins will burn 249 cals (996kj)

PWS without normal growth hormone

The imbalance in PWS of having low growth hormone production means exercise will be harder for them. Decreased quantity of muscle tissue accounts for the difference in energy expenditure, so with low muscle tone it is harder to exercise. For a person with PWS, Growth hormone treatment (GHT) makes a vast difference in muscle tone, and increases the ability to exercise and keep up with their peers.

Fat is the enemy - check the food labels

Excess energy (that is, more than enough food) which is not burned off as exercise, will be stored as FAT regardless of whether it is protein, carbohydrate, or even alcohol. If the intake of food is not balanced by the exercise, the end result will be weight gain. Humans are hard-wired to store fat and we know that fat is the hardest and the last food group to burn off. So, reading the label back of a packet that tells you what is in the product becomes imperative.

  • Check the calories/kilojules
  • Check the fat content
  • Check the sugar content (remember one is as bad as the other)
  • Make sure you understand the label - it might give figures for 100g when the actual content is 150g.
  • "Lite" does not mean fat-free
  • "Fat Free" often means sugar high
  • "Energy" means calories
  • Check one product against another similar one. You may be surprised at the difference.

Small changes can give big results. To achieve weight loss, if you make three small changes a week and lose 200-250 cals from the daily intake, over the course of a year, this will result in weight loss of over 11kg.

You can do it!

Preparing the food

  • You (parent/caregiver) can cook the meals yourself
  • Or you can supervise and assist with the cooking
  • Or you can have food brought in daily
  • All food must be locked away
  • If you have a fridge that is accessible to the person with PWS, keep only "free foods" in it, otherwise it must be locked.

Be inventive:

Because 1,000 cals (4,000kj) isn't very much, you need to be inventive

  • Use smaller plates
  • Plenty of small pieces on a plate look more than one large piece
  • Use free foods (or low-calorie foods) to bulk up the meal (for instance, you can get more fish from a 300g helping than you can beef)
  • Be decorative with the food - make it look attractive on the plate
  • Make kebabs of fruit and raw vegetables
  • Freeze fruit pulp and water as iceblocks in the summertime
  • Have low-fat dips with plenty of vegetable sticks for dipping

Change your cooking methods:

  • Stirfry
  • Grill
  • Bake
  • Microwave
  • Steam
  • Use non-stick pans
  • Instead of using oil to stir-fry, use vegetable or chicken or beef stock