For quite a long time, there has been quite a debate going on in some nutritional circles about what causes obesity and how we should tackle it. One faction has argued that dietary fat is the main offender, and the solution is a diet that is low in fat (and calories). Another faction (of which I’d say I am a member) typically argues that carbohydrate is more of an issue, specifically forms of carbohydrate that provoke much in the way of secretion of insulin – a hormone that stimulates the deposition of fat in the fat cells.
In quite recent times, the debate appears to have shifted somewhat, in the blogosphere at least. The ‘low-carbers’ now find themselves more in a debate with those who popularise and believe in the notion that obesity has something to do with ‘food reward’. I might mangle this, but food reward is essentially the pleasure one derives from eating certain foods. The more rewarding a food, the more we tend to eat of it. In general terms, chocolate biscuits are a high reward food while raw almonds, say, are low.
One part of food reward theory states that different people derive different levels of reward from a specific food and that, overall, obese individuals derive greater reward from food and are basically driven to eat more than lean individuals. The food reward concept has been popularised by several people, of whom Stephan Guyenet over at the Whole Health Source blog is one of the most prominent. As an aside, I have a lot of time for Stephan and have learned a lot from reading his blog.
To be honest, I’ve engaged hardly at all with the ‘low-carb’ v ‘food reward’ debate. I actually think there’s a lot to the food reward concept, but one of my main interests in practice is helping people takes step to improve their health and, for me, low-carb principles are generally highly useful and effective here.
So, if I see someone who wants to lose weight, and I see their diet is rammed full of carbohydrate, I’ll usually talk about the impact of this sort of food on insulin and the effect of insulin on fat storage. Now someone has a tangible explanation for their weight issue that goes way beyond the ‘you’re a bit greedy and need to exert more self-control’ line. Plus, the solution is self evident. And most importantly of all, the vast majority of people in this situation who scale back their carbs will enjoy satisfying weight loss, enjoy what they’re eating, and not be preoccupied with hunger.
Imagine, though, if I bought wholeheartedly into food reward theory. What are my and my patients’ options now? Do I basically tell overweight individuals that they’re eating food that’s ‘too rewarding’, and what they need to do is eat a bland diet or something similar? I’ve never done this, but I’m not sure how well it would land, generally speaking. I don’t know, but I’ve got a feeling many would not find this much of an inspirational message.
The impact of competing dietary theories on the ground came home to me this week when I received an email from a 48-year-old lady. She has had evidence of diabetes in pregnancy, and her mother was diagnosed with type 2 diabetes later in life. Ordinarily, this is just the sort of person I would recommend eat a low-carb or ‘primal’ diet. She had, in fact, taken it upon herself to do this, and was enjoying very good blood sugar control. She’d also successfully lost weight with this approach.
She’d recently read about food reward theory (and, I assume, the notion that carbs aren’t so bad, after all). She put more carb back into her diet in the form of yams (a root vegetable). Guess what? Her blood sugar levels spiked as a result. Her email asked for my opinion and advice.
I told her that for someone with her history, I’d generally advise against much in the way of starchy carbs. It makes no different to me, quite frankly, whether yams for her are a low or high reward food – when she eats them, her blood sugar levels go out of whack. This is really all that’s important. Dozens of researchers and bloggers can (and do) theorise all we like about what causes obesity and what to do about it, but at the end of the day the only thing that truly matters for this lady is that she does not tolerate carbs at all well, and that eating less of them allows her to control her weight and her tendency to diabetes.
In many ways, this lady is a perfect embodiment of why I feel a bit detached from the ‘low-carb’ v ‘food reward’ debate. With people like this her (and many, many like her I might add), I believe no debate is necessary.