Earlier this week my eye was drawn to this report. It concerns the attempts of a professor of human nutrition at the Kansas State university in US to prove that weight management is down to caloric balance and nothing else. The experiment appears to counter the idea that low-carbohydrate diets have merit over those richer in carbohydrate. Here’s the ‘experiment’ in a nutshell:
Professor Mark Haub ate several hundred calories less a day than the amount estimated to be necessary to maintain his weight. He ate mainly sugary, carb-rich junk food each day. After 10 weeks, his weight had dropped 27 lbs and he’d lost significant body fat too. The conclusion: it doesn’t matter what you eat if weight loss is the goal, it’s only calories that count.
While I do not buy into the ‘it’s only calories that count’ school of thinking, I do believe that inducing a caloric deficit of several hundred calories each day is likely to being about weight loss. I don’t know anyone, in or out of the ‘low-carb community’ who would dispute this (though I accept some people may hold this view). The point is Professor Haub has demonstrated through personal, anecdotal experience that the vast majority of people would not dispute. He has, in effect, demonstrated what most people would be regarded as something entirely predictable. Nice work Professor Haub.
If Professor Haub was in any way genuinely interested in exploring the relative merits of different types of diets he might at least have put himself on a different diet at a different time, but at the same time keeping calorie intake the same as the junk-fuelled diet.
Whether he found a difference in effect or not would still not tell us much, however. After all, truly scientific experiments tend to need to use more than one subject to have enough power to discern any difference in the effect of two approaches.
There is at least some evidence that the ratio of ‘macronutrients’ (fat, carb, protein) may have some bearing on weight loss in a way that goes beyond mere calories. Whether this is the case or not is not yet well established, in my opinion, but the point is we have certainly got no further to the truth as the results of Professor Haub’s ‘experiment’.
Leaving this issue aside, some argue that low-carb diets have benefits for those seeking to lose weight because they tend to be more satisfying. That means individuals are more likely to find such an approach sustainable in the long term. I’ve certainly had a lot of personal experience here, and the science supports this too: individuals who cut carbs do tend to eat less quite automatically and without undue hunger. Many of the individuals who have read and acted on my last book (Waist Disposal) have found they have lost weight eating a diet that they enjoy and leaves them satisfied. See here for reader reviews regarding this.
In this book, I review the evidence pitting low-carb against low-fat diets. Putting the relevant studies together I found that low-carb diets, overall, bring about twice as much weight loss as low-fat ones.
But good health is not only about healthy weight, it’s also about other things including wellbeing and health. And here, again, the studies show that overall low-carb diets trump low-fat ones in terms of disease markers including blood sugar and blood fat levels.
Professor Haub’s ‘experiment’ has had a lot of attention, but needs to be seen for what it is (a piece of non-science that tells us nothing we did not know already). Worse than that, it’s being used to propagate the idea that it’s only calories that count. Methinks ‘Professor’ Haub needs to hit the books again and remind himself of what true science is.