Will A Low-Carb, High Fat Diet Work For You?

Low carbohydrate high fat (LCHF) diets aren’t new; they go back centuries and have been reinvented over and over in slightly different guises.

Current favorites include Atkins, Paleo and more recently, a contemporary version of the 19^th century Banting diet. The popularity of these diets in general is incredible, even though there is just about as much disparagement from a number of sectors including some doctors, nutritionists and dieticians.

I have tried many diets over the decades (including Atkins in my teen years) and quite frankly have never found one that worked for me long term. I was never obese so it didn’t matter majorly, but I did yo-yo over the years. To be honest, the diet that probably worked best for me ever was Patrick Holford’s Low-GL Diet that measures food according to a Glycemic Load that relates to what’s happening to your blood sugar. It worked particular well for my husband. 

Happily my weight has stabilized without conscious dieting, though it’s probably got more to do with regular exercise than food. Still I have been drawn to the basics of a LCHF diet because there is so much about it that I have followed instinctively over the years. I’m not a huge meat eater but I do like a bit of crispy fat on lamb chops and streaky bacon is always a winner. I’ve always liked cheese, butter and full-cream milk and yogurt, and have been naturally suspicious about margarine. I also enjoy fruit (though it’s not preferred in most LCHF diets), veggies and salads. So when local South African Professor Tim Noakes (co-founder of the Cape Town-based Sports Science Institute of SA) launched his perceived-to-be-controversial LCHF new-world Banting diet in 2013, I was hooked on the idea. I haven’t followed the diet (which is also promoted as a diet for life) but have joined several Facebook groups that have been set up to support those who do. I also know a number of people who do follow the diet, some religiously. The short- and medium-term results in terms of weight loss are absolutely astounding, as thousands of before, during and after photographs posted on FB show.

Tim Noakes And Banting

The following that Prof. Noakes has attracted since he and three co-authors (a nutritionists and two chefs who are also athletes) published the best selling book The Real Meal Revolution in 2013 is legendary. I think that even the best-selling author of the original Atkins Diet, cardiologist Dr. Robert Atkins, would be envious.  But Noakes and co. have also attracted huge criticism, just as Atkins did.

Importantly, while the diets these two men promoted are both low carb coupled with high fat, they are substantially different to one another, particularly because the Atkins diet calls for much higher protein content. However both are ketogenic, relying on ketosis (or lipolysis), which burns body fat as fuel. Because carbs are removed (or minimized) in the diet, the liver converts existing body fat into ketone bodies that the body uses for energy; at the same time, any carbs are converted into glucose, which is vital for brain function. Both also reduce insulin resistance and stabilize the production of insulin, which is very good news for diabetics.

Then there is the original Banting diet devised by William Banting in the mid-19^th century. Stating that he had previously eaten much too much bread, milk, butter, beer, sugar, and potatoes, Banting gave up milk and sugar, and potatoes and started eating lots of protein in the form of meat and fish, as well as fruit. He also avoided pork because of its “fattening character,” as well as salmon, because of its “oily nature.” While he also gave up champagne, port and beer, he continued to drink claret, sherry and Madeira with his dinner (lunch) and evening meal. He also commonly had a nightcap of claret, sherry, gin, whisky or brandy. He ate four regular meals every day, and always had the nightcap.

Banting’s then revolutionary diet is in fact very different to the so-called Banting diet conceived by Prof. Noakes (see next page) that advocates eating only when you are hungry; encourages dairy products, particularly butter, cream and cheese; and discourages (though doesn’t forbid) drinking alcohol. It was though a low carb diet, and Banting admitted later than he should have avoided, not only potatoes, but also carrots, turnips, and beetroot, which are of course also root vegetables. 

One thing that Banting, Atkins and Noakes have in common is that all three devised their diets to help themselves. William Banting was a morbidly obese undertaker who lived in London. A short man just 5 ft 5 ins (1,65 m) tall, at the age of 65 years in 1862 he weighed 202 lbs (nearly 92 kg). When he published his book titled Letter on Corpulence, he had lost 35 lbs (nearly 16 kg) and was close to his goal weight. In a later addenda to his book, he reported that he had lost a total of 46 lbs (more than 20 kg).

Dr. Atkins was also grossly overweight, weighing in at 224 lbs (100 kg) in 1963 at age 33. He started by removing all sugar and starch (carbs) from his diet, and then increased both protein and fat.

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Prof. Noakes is a character in his own country (which of course also happens to be mine), and had already carved a place for himself in terms of advocating dietary principles before he turned to a LCHF diet. A dedicated athlete who has completed more than 70 marathons and ultra-marathons, he once preached the lore of carbo-loading before running. The son of a man who died of diabetes, when he found he was “pre-diabetic” (resistant to carbohydrates) and had a very high risk of developing type 2 diabetes, he cut the carbs and increased the fat content of his diet. After five months Noakes reported that he was at his lightest weight in 20 years, and was also running faster than he had in 20 years.

Benefits Of Banting And Other LCHF Diets

There is something intensely personal about our choice of diet, but most people will agree that a diet that makes you feel healthy and well, and keeps your weight within the accepted body mass index (BMI) is a good one. A highly respected scientist, Tim Noakes is the first to say that LCHF diets are not for everyone. But one thing he is adamant about is that the benefits of a low-fat diet are myths, and that low-fat eating is unhealthy for anyone who suffers from insulin and carbohydrate resistance. He also maintains that not only will a LCHF diet enable obese individuals to lose weight and achieve an acceptable BMI, but they can also reverse all “known coronary risk factors.”

Some researchers agree with Noakes and the other advocates of a LCHF diet; others vehemently disagree.

The Tim Noakes Banting Diet

Unlike most other diets (including the original Banting) there are no set meal times, no portion sizes and no restrictions on kilojoules in the Tim Noakes Banting diet. Instead it involves eating minimal carbs (absolutely no sugar); loads of good, healthy fats; and moderate quantities of protein. Unlike Atkins, it is not a high protein diet.

Pointing out that it is carbs that make us fat and not fat, the authors of The Real Meal Revolution set out to show us that “fat is your friend,” and “insulin – the devil within.” The bottom line, they say, is that insulin (which is our bodies’ defence against carbs) transforms carbs and glucose into fat and then stores the fat so it cannot be used … and we get fat.

1. The green “all-you-can-eat” list specifies dairy, fats, flavorings and condiments, nuts and seeds, sweeteners, and vegetables that have a carbohydrate content between zero and 5 g, as well as animal proteins up to 100 g (3,5 oz.) 
2. The orange list that contains foods that can be eaten with circumspections, specifically fruits, nuts, vegetables and honey that contain between 6 g and 25 g carbs per 100 g.
3. The red list that contains all the foods that should be avoided, either because they are high carb (like potatoes and other root vegetables) or toxic (like soya and seed oils.)

Most members of the two Banting FB groups I belong to report that they feel more energetic after a week of Banting. Not all lose weight immediately, but most start dropping inches. Again, the before-and-after photographs posted by those following the diet are incredible.

What Research Tells Us

If ever there was an area of research where studies continuously supply conflicting results, it is high fat versus low fat diets. The only area they sometimes agree on are that seed and vegetable oils (which are polyunsaturated fats) including sunflower, corn, safflower and canola oils, are potentially harmful to the body because they are highly oxidized. They also agree that partially hydrogenated oils and trans fats are also bad and should be avoided. But that’s where it ends.

So here's what some recent research tells us:

A study published by the University of Boston’s Department of Medicine in 2013 looked at the effects of a high fat low carb diet compared to a low fat high carb diet on weight loss, cardiovascular risk and inflammation in obese individuals aged 21 to 62. The study was carried out over a 12-week period, and they found that the LCHF group benefitted most. Even though it was a small-scale study, they concluded that LCHF diets may be more beneficial to inflammation and cardiovascular health of obese adults.

Just last year (March 2014) a research report published in the American Annals of Internal Medicine stated that the current available evidence “does not clearly support cardiovascular guidelines that encourage high consumption of polyunsaturated fatty acids and low consumption of total saturated fats.” The purpose of the study was to summarize existing evidence relating to associations between coronary disease and fatty acids. This was based on guidelines that advocate changes in the consumption of fatty acid to promote heart health.

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The team of researchers from the UK Universities of Cambridge, Oxford, Bristol, the Imperial College in London, as well as the US Erasmus University and Harvard School of Public Health looked at 72 studies that had considered links between coronary disease and fatty acids. They found no significant evidence that omega-3 and omega-6 polyunsaturated fats protect the heart or that saturated fats increase risks of heart disease.

Walter Willett, chair of the Harvard School of Public Health’s Department of Nutrition immediately warned that the researchers conclusions were “seriously misleading.” One issue he highlighted was what would replace saturated fat if it was removed from the diet. If replaced with carbs or sugar risks of heart disease would stay the same, but if replaced with healthy fats (for instance olive oil, other plant oils or nuts) then risks would be reduced.

The National Health Services (NHS) UK said that since some people in the studies had cardiovascular disease or suffered cardio risk factors, the results might not apply to everyone. So they recommended people rather stick to current UK fat consumption guidelines that advise cutting down all fats and replacing saturated fat with some unsaturated fat. The guidelines do though confirm that fat is high in energy, and they state that by “frequently eating more energy than you need” (either in the form of fat, protein or carbs) will increase risks of becoming obese or overweight – which can increase cholesterol and increase risks of heart disease.

In September last year, the results of a US randomized trial were also published in the Annals of Internal Medicine. This compared the effects of low carb diets to low fat diets in terms of cardiovascular risk factors and body weight. A total of 148 men and women without diabetes or clinical heart diseases participated and the low carb diet proved to be more effective on both counts.

In opposition to these recent findings, a very small National Institutes of Health (NIH) study published in August this year found that restricting fat in the diet resulted in a much higher loss of body fat than achieved when carbs were reduced. The study involved only 19 men and women, all of whom were obese, and none of whom were diabetic. Their findings hinged on the fat that the reduced-carb diet effectively lowered insulin secretion that increased “fat burning.”

Closer to home (for Noakes and co), a recent study carried out at the University of Stellenbosch in South Africa looked at the effects on heart disease risk factors and weight loss of low carb diets. Using existing research on the effects of high-protein high-fat diets on heart health and weight loss, they found that neither had an advantage over the other. A bit of an anticlimax that really doesn’t tell us anything!