Recently I became interested in the I Quit Sugar program, made famous (?) by Sarah Wilson. I’d looked at it before, partly motivated by a friend of mine who’d lost quite a bit of weight by following it. She actually reviewed the book on her blog. My parents also lost quite a bit of weight by “giving up” sugar, although they didn’t do Sarah Wilson’s program.
Sarah maintains that the real enemy in the Western diet is fructose. Apparently (she’s sketchy on the biochemical explanations) fructose “cannot be utilised by the liver” and is converted straight to fat. Hmmmm. She quotes (repeatedly) a paediatric endocrinologist who is credited with this metabolic pearl of wisdom.
I’m not an endocrinologist and I didn’t do brilliantly at university biochemisty. I cannot draw the Krebs cycle or whatever cycle it is that fructose features in. But even if fructose IS “converted directly to fat”, this theory of it making us fat, to me, still seems highly flawed.
This is my reasoning as to why this is rubbish:
Our bodies burn energy (calories) through a) intentional activity ie exercise and b) metabolic processes such as generating body heat and digesting our food, which add up to a figure known as our basal metabolic rate, or BMR. Our BMR is mainly determined by our gender, our age, our weight, our body composition, disease states and medications and is far more significant than voluntary activity when it comes to burning calories. In the short term, we have no voluntary control over our BMR (we can change it in the long term by altering our body mass or composition or by taking drugs, but we can’t decide to “ramp up our BMR” one day and slow it down the next.)
Our bodies obtain energy to fuel these processes through the food, or calories, we eat (and drink).
If we consume more calories than we expend, we store the surplus as excess body weight. If we consume less than we expend, we obtain the deficit by burning off body weight, and if the two are equal, we are in equilibrium and we stay the same.
Now, Sarah Wilson maintains that all the fructose we eat gets turned into fat because our bodies can’t “use” the calories in that fructose. Ok, let’s assume that she’s right. So, take a person who consumes the same number of calories as they expend. Assume none of it comes from fructose. Great. They burn what they eat, and stay the same weight. Now take someone who consumes, say, 30% of their calories in the form of fructose. Their livers can’t use those calories and covert it to fat. But then they are short that 30% of their caloric requirement. So what happens? Surely that person obtains the shortfall from their glycogen and then fat stores? So they may be “putting on” weight from the fructose calories, but they ought to be burning an equal amount of weight to obtain what they supposedly can’t get from the fructose. So it balances out.
Critics of the CICO (calories in calories out) model will say “Oh but not all calories are equal, some foods require more energy to digest so they actually don’t give your body all the calories they contain.” Yes that’s probably true, but I am very doubtful it makes a significant difference, especially in a balanced diet. The same would also potentially be an argument for this whole fructose theory- if fructose is effortlessly converted to fat while other substrates use up a lot more energy in that conversion then perhaps Sarah’s onto something. But I doubt it.
Don’t get me wrong, I think sugar is way too prevalent in our diet and I am not for a minute suggesting a high sugar diet is good, or even “not bad” for us. But I don’t think there’s anything magical about fructose. I am extremely cynical about all those other “natural” sweeteners too- stevia, agave, rice bran syrup (like, HELLO!!! cane sugar grows naturally and abundantly in far north Queensland- I’m not sure why it’s considered “unnatural”)
But this is why I think we should minimise our sugar intake:
- Sugar is high in calories
- Sugar has no other nutritional value, ie it provides us with no good stuff apart from energy (sure if you were starving this wouldn’t matter so much but there are other more nutritious sources of energy for most of us)
- You rarely eat sugar by itself. It’s usually combined with other calorie dense, nutritionally sketchy ingredients, like fat and white flour, to make tasty “treats” that are ok to eat from time to time, but most of us indulge in a bit too often, in quantities which are too large.
The final nail in the IQS coffin (for me) is Sarah banging on about other pseudo-scientific rubbish (actually there’s nothing pseudo about it, it’s just un-scientific). She advocates “activating” nuts and seeds, “sprouting” legumes, “fermenting” vegetables and drinking apple cider vinegar which allegedly helps “alkalinise” our bodies yet somehow also gives the hydrochloric acid in our stomachs a helping hand with digestion. (Never mind university biochemistry, it doesn’t sound to me like she did much high school chemistry either). All these processes are supposed to “help” our bodies digest and absorb the goodness from these foods. Seriously? How did the human race ever manage to evolve without the assistance of sprouts and kombucha?? It’s a miracle we’re alive at all, thank god for Sarah and other proponents of this twaddle.
In summary, all I’ve taken away from Sarah’s 2 books (borrowed from the library) is that:
- I actually don’t eat much sugar when I think about it- no soft drink, no (well not many) lollies, no store-bought baked goods, no store-bought sauces (thanks zero waste!)
- I should eat more fruit, not less, I don’t care which ones are high fructose
- I should eat fewer cakes and pastries (which I do bake too many of), not because of the fructose but because I am a greedy guts who can’t seem to stop at just a tiny, calorie-controlled, nibble!!
I’m not sure I really needed her to figure any of that out!!