The general loss of efficiency that goes with the loss of functionality has a lot to do with weight loss, moreso if prior to PD you were a good cook who liked decent food.

Before PD I thought nothing of rustling up a wonderful meal, always from scratch, every night. Totally routine for me. It was a pleasure - sourcing it, cooking it, eating it. Breaking bread with family and friends was a big part of my social world in a very commonplace sense. The kitchen was the hub of my life, even while I excelled in my work outside the home. I was a home cook to professional standard. And I have a savoury tooth rather than a sweet tooth, which does not lend itself to weight retention in times of struggle. Prior to PD, I consumed vast amounts of food, but just never had a taste for the crappy stuff that is now mandatory to keep up with the calorific demands of rigidity and pain. I was always slim, even when I ate loads. Now, unsurprisingly, I am constantly underweight.

For me, one of the awful ravages of this disease, is not being able to move around my kitchen with the efficiency that produces great food [and the ability to clean up the ensuing mess in ten mins]. Preparing a great meal was my means of relaxing after a day's work. Throw on a good CD, open a bottle of wine and start chopping the onions and garlic.

'Effortfulness' is the strain that needs articulating in terms of understanding PD - all aspects of it. The effort of keeping the fridge full [when walking, driving, carrying groceries gets hard], cooking, cleaning up. Just swallowing enough when eating slows down - before your brain gets the 'full' signal.

Healthy people do not recognise and account for how much of their survival, and ability to thrive, depends on the balance of inputs and outputs in terms of fuel and energy consumption. When you can't move around properly you can't keep yourself warm, you burn more energy. If you don't sleep properly because of pain, you burn more energy. And so on ...

You begin each new day in a state of negative equity, energy wise. Pretty soon you are in trouble.

Why are we surprised? In times and places where there is famine or war, it takes about three days of restricted access to food to reduce people to a marginal state of nutrition unless they were obese to begin with. It doesn't take long to become too weak to seek, prepare and consume a proper diet. Illness can put people in this predicament quite rapidly.

The social aspect of having someone to share meals with is very important. It is the reason many elderly people living alone do badly, even if they don't have a major disease. Food is about more than nutrition. It is a highly social activity that maintains social relations - mealtimes are ritualistic, social life everywhere with good conversation revolves around them. Mealtimes are when people recount the events of the day, tell one another stories, make one another laugh, connect with loved ones. Whatever jeopardises this, compromises health, surprisingly rapidly and in ways which are not adequately credited.