Striving for balance in the diet debate
Both sides have merit, but some dietary facts are not in question
THE Heart and Stroke Foundation SA (HSF) would like to respond to the debate initiated by Professor Tim Noakes on protein and fat loading.
We all know that taking in fewer kilojoules will result in weight loss – so yes, a high-fat, high-protein, low-carbohydrate diet will give you weight loss. But so does a low-fat diet. In fact, following any diet that decreases kilojoule intake will result in weight loss in the short term. Yet we know many people revert to their old eating habits and regain the lost weight, plus more.
We do support Noakes’s argument in part; however we also support the arguments presented by some of Cape Town’s cardiologists, noting that both messages hold merit.
At the same time we have the responsibility to present facts and correct misperceptions evident from comments coming from the public.
Type of fat is important: the HSF does not say “no” to fats! But the message is more nuanced. For good health we need some fat in our diet. The real issue is the quality of fats we eat, against the total kilojoules in the diet.
While studies are unclear about the effect of saturated fats on health, there is solid proof that replacing saturated fats with unsaturated fats will improve cholesterol levels, reduce heart disease risk and prevent insulin resistance, a precursor of diabetes. Eating good fats in place of saturated fats lowers the risk of heart disease. Replacement is key.
Very bad fats: we trust that Noakes is not recommending that people increase their trans-fat intake (this is a fat too). We know that trans fats significantly increase the risk for cardiovascular disease (CVD) and so should be avoided.
Not all carbohydrates are bad: there is no doubt that unrefined carbohydrates are healthy and protective against certain diseases, including cancer. Refined carbohydrates, on the other hand, should be treated with caution – if there is one thing that everyone agrees on, it is this. The real issue is the abundance of refined carbohydrates found in most everyday foods we eat.
In reality, when people cut back on fat, they fill up on foods full of refined carbohydrates (eg white bread, sugary drinks) or use fat-free products without the healthy fats and which contain hidden sugars. The result is an increased risk for obesity, CVD and diabetes, which is why we recommend replacing foods high in bad fats with foods high in good fats – not with refined carbohydrates.
Then there is matter of over-simplifying the causes of heart disease. It is common knowledge that the causes of heart disease are multi-factorial, and are not exclusive to only blood cholesterol and a high fat diet as claimed.
As the Harvard School of Public Health reminds us, “looking at a single nutrient in isolation cannot tell us the whole story about a person’s heart disease risk”.
To ignore other contributing factors, behaviours and living contexts that lead to heart disease would be erroneous and dangerous. DR VASH MUNGALSINGH Chief Executive Officer Heart and Stroke
Foundation SA