The hot topic of controversy that has challenged so many qualified dietitians in South Africa is associated with the Banting or the low carb high fat (LCHF) diet.

This has been promulgated by professor Tim Noakes, a professor of exercise and sports science at the University of Cape Town. He has run more than 70 marathons and ultra-marathons and is the author of several books on exercise and diet.

Although his original books included the use of carbohydrate loading (carb-loading) for exercise events, he has now gone so far as to remove those sections from his books. He is now known for his book called the Real Meal Revolution which has currently sold approximately half a million copies.

For those who are interested, the official site at Realmealrevolution.

There are many opinions around the Banting Diet and the LCHF philosophy, some positive, some negative. The professor markets himself very well and the people of South Africa, being predominantly fatty meat lovers, have followed his plan and have lost weight with great success. People with diabetes are seeing great results in their blood glucose values too.

However ,so too have those who have followed other similar fad diets.

The medical profession, including cardiologists are up in arms, yet the public demand for this diet is growing to the extent that supermarkets are selling LCHF products including low carb bread (valued at about R80 a loaf, normal cost about R12). Restaurants also have Banting friendly options on their menus.

Why are people losing weight? They are ultimately eating fewer calories.

One advantage of this way of eating is that people eliminate all the highly refined carbohydrates that they previously ate, such as biscuits, muffins, sweets, chocolates, chips, etc. There’s no argument that this is a good feature of the Banting diet.

Another positive is that followers increase their vegetable intake. This is something dietitians are always trying to get patients to do. These are some of the bonuses.

However the downsides are that followers are practically removing all fruit from their diet. Fruit is one of our protective food groups.

Whole grains, fruit and vegetables are also cardio protective (protect the heart and blood vessel system) due to the synergistic effect of all the vitamins, minerals, fibre, anti-oxidants, and other phytonutrients. These are all vital for health and immunity. Removing the sources of these key natural protective agents from the diet is detrimental.

The lack of good quality carbohydrate in these high fat diet regimes often results in suboptimal fibre intake that increases the risk for cardiovascular disease (CVD).  We know there is plenty of evidence for the fibre content of the diet being beneficial in reducing CVD.

The Banting diet being high in fat, is advocating more specifically a diet high in saturated fat. Traditionally a diet high in saturated fat (SFA) affects LDL cholesterol and has been associated with an increased risk for CVD. There has been some recent research to show that the risk analysis is quite complex and that people with a high SFA intake had a similar incidence to developing CVD as with a lower SFA intake. This all thus promotes the high fat diet that is being so closely adhered to.

But, recent research has also shown that the effect of SFA on total cholesterol and LDL cholesterol depends on the amount of good fats in the foundation or background diet and it appears to be more detrimental when the diet is low in polyunsaturated fats (PUFA) and is high in cholesterol and red meat.

We need to remember that the effect of a single nutrient cannot be measured in isolation as food contains a combination of nutrients.

The efficacy of low carbohydrate diets (LCD) in subjects with Type 2 diabetes has divided the nutrition community. My colleague, Hamish Van Wyk, who works in Port Elizabeth, sought to critically review the available data to clarify misunderstandings. 

He did a thorough scientific search looking at MEDLINE, EMBASE, Cochrane Database and CENTRAL and he found 8 meta-analyses identifying 110 studies exploring LCD in Type 2 diabetes. The inclusion criteria for his search? They had to be a randomised controlled trial (RCT) of longer than 4 weeks, use a carbohydrate intake of less than 45% total energy, and include a dietary intake assessment at the end of the study.

For various reasons including flaws in the studies, only 12 studies ended up being included and evaluated.

The results actually showed that there was no significant difference in glycaemic control, Body Mass Index or waist circumference between LCD and the traditional "higher" carbohydrate diets.

Interestingly, in some of the studies the difference in carbohydrate intake of the LCD and traditional was only about 8 grams, suggesting that the diets all converged towards a more moderate carbohydrate intake.

We do, however, need to question the sustainability of very low carbohydrate diets that contain less than 50 grams carbohydrate daily. That’s a hard diet to keep following.

In conclusion, a lower carbohydrate intake may help some people and cutting out refined carbohydrates is definitely beneficial.

For weight loss though it still boils down to total energy intake. Creating energy deficits facilitates weight loss.Consume fewer calories (kilojoules) than you need to lose weight.