Okay. It’s nearly the end of week one of Vegan Challenge Month and contrary to the numerous accounts of feeling “lighter,” “healthier,” “energised” and “rejuvenated” after eliminating all animal-derived products from one’s diet, at this point in time all I can report is feeling TOTALLY, INSATIABLY, CONSTANTLY HUNGRY.
So I did my research, and I suspected as much:
Both animal and human studies show that consuming protein, as compared to carbohydrate and fat, promotes stronger feelings of satiety and suppresses food intake at the next meal. In humans, visual analogue scales (which use a scale to measure how hungry a person is) and food intake are often used to measure satiety. In addition, changes in hormone levels that affect appetite can provide a closer look at how the three macronutrients impact satiety and hunger. Cholecystokinin (CCK) is an intestinal hormone that is released after a meal and signals satiety. Increased levels of peptide YY (PYY) signal satiety, and ghrelin levels increase when we are hungry. In addition to altering our feelings of satiety, protein-rich meals stimulate CCK and inhibit ghrelin, providing a biological explanation for how protein works to influence satiety.
There you have it. Protein consumption stimulates the satiety hormone and suppresses the hunger hormone. (I suddenly get the feeling we’ve been over this before…)
I can’t say I didn’t already feel energised, healthy and light – I do a lot of running and not a lot of eating meat anyway, but I wasn’t expecting such a marked increase in my appetite. Vegan Monday, Tuesday and Wednesday went swimmingly. On Thursday I was hungover and have been at home for the last few days. I’ve been racking my brains and have come up with a combination of explanations as to my recent bear-about-to-hibernate-like eating patterns…
1. I’ve inadvertently reduced my protein intake and am therefore releasing more hunger hormones – coming home on Thursday to my parents’ not-so-vegan-friendly house (love them though I do, of course) where your best bet for protein is chicken or cheese probably didn’t do much to help matters.
2. The colossal amount of sugar I consumed in the form of cocktails on Wednesday night resulted in spending Thursday constantly craving quick-fix carbohydrates which in turn resulted in a vicious cycle of hunger and cravings and bingeing.
3. Carb0loading and running the marathon did something weird to my hunger levels for the following week and a half, and now my appetite has suddenly returned with a vengeance.
These things coupled with the fact that I’ve been exercising like a mad thing – and really was eating next to nothing at the beginning of the week because, in a strange, sick way, I relished the notion of not having to eat in order to fuel a marathon training plan – have apparently resulted in an explosion of hunger that needs to be addressed.
It all seems to have been a little too much for my body, my metabolism and my brain to handle – eating an extra meal a day, running 26.2 miles, suddenly losing that ‘extra meal’ and then losing all dairy products the week after, in which I also embarked on my new run/yoga/cycle/swim exercise regime – maybe I just need to tone it all down a little bit.
Having said that, I don’t actually feel all that guilty about the entire punnet of syrup-covered dates that I ate whilst waiting for my train the other day…
See you in Wagamama’s this evening with my not-vegan and not-happy at not-being-able-to-get-pizza-tonight boyfriend ! (Love you, Gareth !)
Marie Spano, 2009, Protein and Satiety, available at http://www.foodproductdesign.com/articles/2009/08/protein-and-satiety.aspx (accessed 28th April, 2012)