Low-carb eating has again demonstrated its superiority to a low-fat diet. (Louise Valentine/The Epoch Times)
The conventional view is that the diet should be low in fat and high in carbs. Fat, we are told, makes us fat, so eating less of it is the sure-fire way to keep lean and healthy. On the other hand, some argue that it’s not too much fat that makes us fat, but too much carbohydrate. Such individuals will advocate a low-carb diet, which may (but may not) end up being quite rich in fat.
In this column I have referred to studies that show that low-carb diets outshine low-fat ones in the weight-loss stakes. I’m not aware of one single study that found a low-fat diet to be superior in this respect.
Those that cling to the idea that low-fat is the way to go will very often resort to claiming that low-carb diets are unhealthy, often on the basis that their sometimes high-fat content will put people at risk of cardiovascular diseases such as heart disease and stroke. I have to say I’m unmoved by this argument for two main reasons.
First, there really isn’t very much evidence linking supposedly unhealthy saturated fat (found mainly in meat, eggs, and dairy products) and increased risk of cardiovascular disease. Neither is there much (if any) good evidence that eating less saturated fat has broad benefits for health.
But my other major issue with the argument that low-carb diets are bad for the heart and circulatory system is that studies have found that, compared to low-fat diets, such diets generally lead to improvements in biochemical markers of cardiovascular disease. Many studies have found that lower-carb diets have led to changes in blood-fat levels that would be expected to lead to a reduction in cardiovascular disease risk.
I was interested to read of a study published very recently that sought to review the evidence in this area [1]. Thirteen studies in which low-carb diet were pitted against low-fat ones were included in the review, and each of these lasted at least six months. One limitation of the study was that the design of the low-carb diets in the individual studies sometimes allowed reintroduction of significant amounts of carbohydrate.
Despite this, the results showed that compared to the low-fat diets, the low-carb ones had generally favorable outcomes, including significantly more weight loss at 6 and 12 months (about 8 lbs. and 2 lbs., respectively), significantly lower triglyceride levels, and significantly higher “healthy” HDL-cholesterol levels.
The low-carb diets had lower attrition rates too, suggesting that individuals have a harder time sticking to a low-fat diet compared to one that is carb-controlled. This is important, since compliance is important if the benefits of any diet are to be sustained.
This review does a good job of assessing the relative benefits of lower-carb and low-fat eating. And it shows, once again, that as a general rule, the former is preferable for the purposes of weight loss and brings superior benefits in terms of cardiovascular risk factors, too.
Reference:
[1] Hession M, et al. Systematic review of randomized controlled trials of low-carbohydrate vs. low-fat/low-calorie diets in the management of obesity and its comorbidities. Obesity Reviews 2008 Aug 11 [Epub ahead of print]
Dr. John Briffa is a London-based physician and author with an interest in nutrition and natural medicine.
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