Study: More weight lost on higher carb diets for some

I saw this quote in a Psychology today article recently “If all you have is a hammer, everything looks like a nail.” (The right tool for the job). It’s not new of course, it’s one we’ve heard often. But as I reflect over my varied careers and life experiences, I  realise how often I’ve fallen into the “hammer trap”, where a particular experience colours my world view profoundly.

It goes like this: Something I’ve tried – whether it be a diet (Zone, Paleo, low carb, raw vegan …, name yours) or some self improvement course, religion, inspirational book, peak experience, adventure, therapy, medication, sport, exercise.. you get the picture. This thing you experience – it changes your life in some way, in fact it makes it profound difference. Every issue / health problem you see others having – your recent discovery appears to you be the answer.

As a group of paleo nutrition, and often low carb advocates – we tend to view the world’s health / weight problems as though paleo / low carb is the answer to everything. E.g. low carb will fix everyone who is overweight, it’s even good for athletes once they get used to burning fat instead of carbs…

I’m not saying it isn’t, I’ve seen incredible results in many people, however – I’m also aware of how science changes and evolves. And how little we really know, and how varied humans are. [Edit: To date I haven't seen any evidence against a 'paleo' paradigm being the best dietary advice - by this I mean removing grains, especially gluten grains, chemically extracted vegetable oil and other nasty fats like trans fats, processed food, multiple synthetic additives and sugars - especially fructose. This is what I recommend across the board. See comments]  I cringe when I think how I’ve had my own past “hammer” of one sort or another and sought to fix everyone’s problems with it. So when we have only one answer to a problem, then we hear it’s not working e.g. ‘low carb’ isn’t working for some-one, we think “they’re not doing it right” or some version of that. Or perhaps we hear that someone added in more carbs and their weight loss increased and their health improved. If it doesn’t fit for us – we then ignore it or try to rationalise it somehow.

Take my Zone days for example – I thought all anyone needed to do was go on the Zone diet and their problem would be solved. Very low carb was incorrect – the body is forced to release cortisol for gluconeogenesis (not good). High carb was also wrong as it caused excess blood glucose and consequent insulin release, and then fat storage and hunger. I got stuck for a while in my view that the Zone was the only way to go.

At University I was given this review article:

Dietary composition and weight loss: can we individualize dietary prescriptions according to insulin sensitivity or secretion status?

If you do have access to the full article – it has a useful discussion on the complexities of insulin secretion, insulin sensitivity, insulin resistance, fasting insulin vs post prandial insulin… (I.e. there is more to the picture than high carbs = high insulin = fat gain)

One studies it referred to was this one:

Insulin sensitivity determines the effectiveness of dietary macronutrient composition on weight loss in obese women.

[NOTE: An important point to note is that any diet that is calorie reduced is likely to reduce carbohydrate calories from previous intake, so don't make the assumption the these women increased their carbohydrate intake from their pre-diet one. The calorie reduction was 30% - so carbs could potentially be 30% less than previous intake]

I have to say at the time I was SO entrenched in low/moderate carb i.e. Zone diet was “THE RIGHT WAY TO EAT” I actually couldn’t get my head around the fact that this study showed that when two different calorie reduced diets were tested some women lost more weight on the higher carb diet. Significantly more than they did on a higher protein, lower carb diet.

My point? Let’s not assume that our “hammer” i.e. what has worked for us is the best answer for everyone else. Their body may run very differently from our own, and a like this study shows may run better on a very different mix of fuel.

Be aware that what has worked for you has highly coloured your world view. Try and put it aside, and you might discover that what the other person needs a screwdriver. Or when they say they are losing weight eating more carbs rather than less, they are not deluding themselves.

More reading: Lyle MacDonald discusses insulin sensitivity and fat loss in this 2008 article: Insulin Sensitivity and fat loss.