A formal, best-worst scaling study published in 2018 shows hyperphagia is “the” aspect of PWS that families want addressed through new therapies, followed by other critical behavioral issues such as anxiety and aggression. This study, which has been shared in ongoing discussions with the FDA, quantifies caregiver priorities and further identifies unmet needs in PWS.

Hyperphagia is the extreme unsatisfied drive to consume food and a hallmark characteristic of PWS There are several approaches frequently used to describe hyperphagia. They include the quantifying of “overeating” as energy intake relative to a control group; eating beyond amount predicted for body size and body composition; and evaluating food intake pre- vs. post-treatment. The evaluation of “hunger” (e.g., with visual analog scales in patients with PWS and controls) which is measured by the time to reach satiation relative to a control group and the duration of satiety. The measuring of preoccupation with food (hyperphagic drive) and food seeking behaviors. And lastly the evaluation of psychological symptoms such as distress and functional impairment.

Until recently, PWS was generally described as having two nutritional stages: poor feeding, frequently with failure to thrive (FTT) in infancy (Stage 1), followed by hyperphagia leading to obesity in later childhood (Stage 2). However, after a longitudinal study followed the feeding behaviors of individuals with PWS , it was found that there is a much more gradual and complex progression of the nutritional phases than the traditional two stages described in the literature. A total of seven different nutritional phases( with five main phases and sub-phases in phases 1 and 2) has been identified. Phase 0 occurs in utero, with decreased fetal movements and growth restriction compared to unaffected siblings. In phase 1 the infant is hypotonic and not obese, with sub-phase 1a characterized by difficulty feeding with or without FTT (ages birth-15 months; median age at completion: 9 months). This phase is followed by sub-phase 1b when the infant grows steadily along a growth curve and weight is increasing at a normal rate (median age of onset: 9 months; age quartiles 5-15 months). Phase 2 is associated with weight gain-in sub-phase 2a the weight increases without a significant change in appetite or caloric intake (median age of onset 2.08 years; age quartiles 20-31 months;), while in sub-phase 2b the weight gain is associated with a concomitant increased interest in food (median age of onset: 4.5 years; quartiles 3-5.25 years). Phase 3 is characterized by hyperphagia, typically accompanied by food-seeking and lack of satiety (median age of onset: 8 years; quartiles 5-13 years). Some adults progress to phase 4 which is when an individual who was previously in phase 3 no longer has an insatiable appetite and is able to feel full.

American Journal of Medical Genetics (2011)

For Clementine, hyperphagia has yet to fully manifest. She is definitely much more “interested” in food than what is considered typical. Clem will ask about her meal schedule for the day. She wants to know what she will be eating for lunch and dinner. It’s important to her that the general meal schedule is known and that it is upheld. If there are to be changes in meal time or to the menu, it will likely cause at least some anxiety so we try to avoid those situations.

Clementine is an “opportunistic ” food seeker. If something is available, she will usually take it. All of our food containing spaces are locked and have been since Clem was about 2 years old. This is because it is very important for someone with PWS to have what is called “food security”. Food security is the removal of the opportunity to obtain food that isn’t authorized or isn’t part of a meal or snack. Having food security is an extremely important part of managing Clem’s anxiety. However, we have 3 other children so naturally there are times when things are left out or something is left unlocked. Clem is very observant and she will notice these opportunities immediately. Almost 100% of the time, she will seize the chance and will take whatever is available to her room. What’s very interesting is that very often, whatever has been taken is then secreted away and not eaten. I can’t tell you the number of times we have been cleaning her room only to find a piece of mummified food that is no longer recognizable! What this tells me is that the food seeking behavior she exhibits is closer to a compulsion than a behavior driven by true hunger.

Clem has not yet developed the overwhelming drive to eat. She will frequently leave food on her plate, particularly if she isn’t crazy about what she was served. Like most people, she has her favorite foods and also a list of things she really doesn’t like. For example, she doesn’t like cheese of any kind and she hates anything that is carbonated (although I think that’s more of a sensory issue). At school, we have not yet had the problem of Clem trying to eat the food of others or attempting to forage through backpacks, lockers etc. One thing is definitely true though.. she will not share her food and gets upset if someone asks to try something of hers or asks for a bite. That will not happen!

Clementine is 11. It’s typically expected for children to hit the hyperphagic stage at around 8 years old. The latter end of the age range for hyperphagia is around 13. We have noticed an increase in her general state of anxiety in the past year. Although the anxiety doesn’t really center around food (usually it’s change to routine), the increase makes me think we are edging closer to reaching stage 3 and hyperphagia. It’s tough as a parent waiting for something you know is inevitable and devastating and right around the corner. The constant thought running through the backdrop of your mind is when will it happen? When will the shoe drop? When will Clem begin to suffer unsatisfiable TRUE hunger?

Here’s the thing that is very important for people to understand about hyperphagia. For the sufferer, although their body might not need to eat, the signals the brain is sending to the body are real hunger signals. The same painful stomach rumbling you get when truly starving. The same mental state that allows you to think about nothing but eating. The hypothalmus is malfunctioning and can’t turn off these signals so they are being sent 24/7. The person is in a state of true starvation in all ways except for nutritional deprivation.

For me as Clem’s mom, it is incredibly difficult to imagine her future being one spent in this hyperphagic state. Her upbeat and sunny personality will surely disappear. The pain of hunger will be constantly at her side and will control most of her thoughts and desires. It will dictate her life and mute all of life’s other pleasures. I think it could best be thought of as one would think of an addiction to drugs and alcohol. The difference is that you don’t need drugs or alcohol to live. But you do need to eat!

Of course, in addition to the physical and mental pain caused by hyperphagia, there are also increased health concerns. If left unchecked, hyperphagia results in morbid obesity. Obesity is a contributing factor in so many chronic and life threatening diseases… heart disease, stroke, cancer, and diabetes just to name a few.

Clementine has T1D. This is unrelated to her PWS but is a perfect storm of circumstances. If she forages for food and eats anything that is not expected and accounted for, her blood glucose levels will spiral out of control and will have immediate health consequences. This just adds another layer of concern and despair when thinking about her impending hyperphagia.

So for the sake of Clem’s health, both physical and mental and for the sake of every other person on this planet living with PWS, a treatment must be found. Treatments are discovered through research. Research is born out of access to adequate financial resources. I have committed myself to the creation of these necessary resources. Will you consider assisting me in my mission?

Clementine modeling the latest RFR PWS youth tee shirt.