Some doctors and dietitians still say a low-carb, high-fat (LCHF) diet is dangerours. That’s despite compelling evidence to show both safety and efficacy of LCHF for weight loss, diabetes, heart disease, cancer and even dementia. Some specialists call dementia type 3 diabetes because of its links with diet.
LCHF is a global phenomenon. In South Africa there are three million fans of LCHF regimens are known in that country. LCHF pioneer is UCT emeritus professor Dr Tim Noakes, a world-renowned scientist rated A1 by the National Research Foundation for expertise in both sports science and nutrition. He documented his theories in the best selling The Real Meal Revolution, co-authored with chef Jonno Proudfoot and nutrition therapist Sally Ann Creed that is known as the “Tim Noakes Diet”. Here, in a Q&A, Noakes gives the basics and an Idiot’s Guide to getting started on the LCHF path. First question:
Is LCHF a diet?
No, it’s a lifestyle.
Do you say your diet’s right for everyone – a one-size-fits-all?
There’s no such thing. No diet is right for everyone. LCHF is best for people who have insulin resistance (the inability to tolerate carbohydrate).
Is it correct to call it “Banting”?
It’s probably more correct to call it Ebstein – after German physician Dr Wilhelm Ebstein who first made it high-fat. That was the diet Sir William Osler promoted in his monumental textbook: The Principles and Practices of Medicine published in the US in 1892.
Is LCHF a fad?
Anyone who claims Banting or Ebstein diets are fads knows nothing about medical nutrition history. Nutrition did not begin in 1977 as our students seem to be taught.
Is LCHF the same as Paleo?
The Paleo diet is slightly different; it promotes consumption of only those foods that would have been available to Paleolithic man from about 2.5 million years ago to the Agricultural Revolution starting about 12 000 years ago. Foods allowed on Banting but excluded on Paleo are dairy; fruits are allowed on Paleo but excluded on Banting.
What about Atkins?
The Atkins diet is similar to Banting. Perhaps Banting promotes the use of low-carb vegetables rather more than Atkins did, but the differences are trivial. This shows that first priority, and the commonality of all these diets, is to cut carbs and sugar (and vegetable oils) and whether you go Paleo or Banting or Atkins is determined by how you respond to the different options in the different diets. To find the ideal low-carb diet you need to experiment to see how you respond.
Is LCHF extreme?
It depends what you mean by extreme. Moderation is a smug, puritanical word. No mammal eats in moderation. In nature all diets are extreme: lions eat only meat, polar bears mainly fat, panda bears only bamboo shoots, giraffes only acacia leaves.
Is it balanced?
Balance is what has worked for each of these species for millions of years. LCHF can be extremely low in carbohydrate – the one nutrient for which humans have absolutely no essential requirement, but that depends on how sick you are. In 1977, when we were told to eat diets extremely high in carbohydrates, human health started to fail on a global scale.
Your recommended carb range is <200g to <25g, correct? What are the indications?
It depends how insulin resistant you are and how much exercise you do. If you are completely insulin sensitive (that is, you tolerate carbohydrates well, have low fasting blood glucose, insulin and triglyceride concentrations, low small LDL particle numbers; low HbA1c; high HDL-cholesterol concentrations; and absence of fatty liver) and exercise regularly a few hours a week, then it is can be safe to ingest up to 200g carb per day, or at least until your HbA1c rises above 5.5% . That’ll be time to start reducing the carbs.
On the other hand, if you are profoundly insulin resistant with type 2 diabetes, morbidly obese, or with heart disease, cancer or dementia, you’ll probably do best on a very low-carb diet of about 25 grams carbs per day. This won’t change even if you do more exercise. Exercise is helpful but doesn’t obviate the need to eat very few carbs, even if you exercise for many hours a week.
What carb-fat-protein ratio is best?
It depends how sick you are. If you’re diabetic, we say 20% to 30% protein, 60% to 70% fat, 5% carbs. The sicker you are, the more fat you need because fat is insulin-neutral. The more insulin resistant you are, the more fat you can eat, because even when the pancreas fails, fat is the only fuel you can metabolize safely without requiring insulin. It’s perfect for blood sugar control.
Any weighing of food on your diet?
No. That’s a joke. You can’t predict accurately the absolute calorie content of foods when eaten by humans. You don’t know how many calories each person needs. The only way to work that out is by weighing yourself. If your weight stays stable, you’re eating the same number of calories you are expending. If you’re lean, that’ll probably be the correct number of calories for your body and activity level. There’s no other way remotely accurate enough to measure your calorie needs. We don’t tell people how many grams to eat daily, except for carbs. If you are really sick or markedly insulin resistant, the key is 25g maximum daily.
Is Banting (LCHF) dangerous for babies?
No. It’s common in many traditional societies such as the Inuit in Canada, the Maasai in Kenya. The choice between health and ill health begins with infants as soon as they’re weaned. Babies should not be weaned on to traditional high-sugar, high-carbohydrate processed cereals. The science behind it is in our book, Raising Superheroes.
What does LCHF mean for infants?
Meat and veg because these are the foods that optimize brain development. The infant brain is growing at a fantastic rate for the first two years of life. The only way to optimize that growth is foods high in what are called brain-specific nutrients. These are found in highest concentrations in real foods, especially seafood and shellfish, but also in dairy, eggs, liver and meat. They are not found in high-carbohydrate, high-sugar processed foods. Meat, liver and fish alone are babies’ first foods in many traditional societies.
Is Banting for babies low-carb?
No, only compared to traditional high-carb, high-sugar, low-fat guidelines.
What’s all the controversy around ketosis – is it really so dangerous?
Ketosis is a perfectly natural condition in which the liver increases its production of ketone bodies (from circulating fats) that can substitute for glucose as a fuel for the muscles, heart and brain. Ketosis from intermittent fasting is probably the natural human state. Indeed in the 1500s Europeans typically ate once a day, not 3-6 times as we now do. We are beginning to realize ketones have many other beneficial effects beyond simply providing an energy source to replace glucose. These effects will become more studied and will add further evidence for unexpected medical values of the low-carbohydrate diet.
Are there different forms of ketosis?
Yes, two important forms of ketosis: nutritional ketosis and diabetic ketoacidosis. They are polar opposites. Nutritional ketosis is one of the most important adaptations in the human body. It allows humans to survive periods of starvation without destroying their brains (from a lack of blood glucose supply). It develops when dietary carbohydrate (and protein intake) is restricted and fat intake is greatly increased in persons who continue to secrete some insulin – and who therefore don’t have type 1 (insulin-deficient) diabetes.
Nutritional ketosis is very different from diabetic ketoacidosis which occurs in persons with insulin-deficient type 1 diabetes, and who are unable to produce even a trace of insulin. Diabetic ketoacidosis occurs mostly in type 1 diabetics who fail to inject sufficient insulin for whatever reason. It is a life-threatening condition for which the treatment is replacement of insulin, and correction of the other metabolic abnormalities including the severe acidosis.
How best to define and differentiate nutritional ketosis and diabetic ketoacidosis?
By the levels of blood ketones that occur in either condition: in nutritional ketosis values are seldom greater than 1-2mmol/L and there is no acidosis; in diabetic ketoacidosis, blood ketone values can go as high as 30-50mmol/L (with an associated and life-threatening acidosis). Remember, the ketones are not the danger here; the acidosis is.
How can people get into nutritional ketosis?
To get into nutritional ketosis you need to reduce your carbohydrate intake to 25g/day, eat less protein and lots of fat. The easiest way to reverse nutritional ketosis within 15-30 minutes is simply to eat some carbohydrate or protein.
Is saturated fat ever a health threat?
It can be, in the presence of a high-carbohydrate/sugar diet that causes elevated insulin concentrations due to the excessive carb intake. Insulin directs an altered metabolism with the formation of the damaging oxidised (LDL) cholesterol that’s probably a key component in heart disease.
What’s the key here?
To eat a diet that keeps blood insulin and glucose concentrations low, because elevated insulin concentrations especially are linked to long-term health problems. We say: eat what your appetite directs you to. Once you cut the carbs we think your brain will tell you if you need more fat or protein. It’s about finding the balance that works for you.
On to LCHF fundamentals: what to cut out?
Bread, potatoes, rice, pasta, pizza, sugar, all grains, cereals, processed, packaged, boxed, adulterated foods, cakes, sweets, biscuits, fizzy drinks, all the addictive things. Anything sweet, starchy has to go, and low-fat foods.
What stays in?
Fat and protein. You can eat fat in relatively unlimited amounts, but only moderate protein. You can’t really overdose on fat; it reduces appetite; it’s the best way to get over sugar addiction.
What are good protein sources?
Eggs, full-fat dairy, cheese, yoghurt, fish, chicken – with the skin, not battery fed – and some meat, preferably organic, or at least pasture-raised, not from animals raised in feed lots and fed grains because that destroys the meat’s quality. Meat’s not a main focus, but we like lamb because it’s fatty and pasture fed.
And good fat sources?
Butter, cream – ladle meat and veg with butter; put cream in tea or coffee. Coconut oil is very healthy, everyone should have two tablespoons daily. Avocados, nuts – almonds, walnuts, pecan nuts, especially macadamia nuts, they are like drops of fat. All tree nuts, not peanuts or cashews. They’re legumes, not nuts.
What about vegetables?
All vegetables have carbohydrates; we recommend those with lowest-carb, highest-nutrient content: leafy greens such as kale, it’s one of the most nutritious vegetables; cauliflower, broccoli, they’re on our green list – (in The Real Meal Revolution).
What about 5-a-day fruit and veg?
It’s unscientific advice.
Is it possible to be an LCHF vegetarian?
Yes, by eating a high-fat version – by including nuts, avocados, dairy and other safe oils, like olive oil. But please, no “vegetable” (seed) oils as these are highly toxic. The problem for vegetarians and vegans is if they are insulin-resistant, their high-carbohydrate vegan or vegetarian diets could cause weight gain and worsen insulin resistance with time.
Is it possible to be vegan on LCHF?
Well, I know a vegan athlete, a former professional cyclist who eats 80% fat in his diet – lots of coconut oil and avos. It’s an extreme diet that works for him. Clearly his gut flora can handle it. I know someone who eats only raw meat. We don’t know what the bacteria in their guts are doing, and how those bacteria might compensate for what we might perceive as intake “deficiencies”.
Some people won’t lose weight on LCHF even when they follow the rules rigorously. Why?
The key to obesity control is to understand the role of the human brain homeostat (appestat) that controls energy intake and energy expenditure. For millions of years the appestat worked perfectly, exactly matching how much we ate to exactly how much energy we expended each day. The controls are so exquisite they must be accurate to within a few calories per day. If not, no human would ever be weight-stable for any length of time.
The appestat works so that if you exercise less on one day, you don’t become fat the next. You simply eat less and maintain the same body weight. Conversely if you exercise more, you don’t lose weight, you just eat more. Unfortunately the appestat doesn’t work the other way: if you eat too many calories (because highly addictive, sugar-rich foods have hijacked the appestat) the appestat doesn’t force you to go out and exercise off those extra calories.
So what’s the real magic of LCHF?
The reason LCHF works so effectively in so many is because it quietens the appestat so that calorie consumption drops without hunger and weight is lost effortlessly. In most people, the reduction in daily calorie intake is probably in the range of 10% to 50% of daily calories, again without hunger. For some, especially women who have experimented with many different diets over the years, this doesn’t happen. Their appestat function has perhaps been “damaged” by years of calorie restriction and hunger; instead of reducing calorie intakes on LCHF, they actually increase their intakes and gain weight.
In some it seems that instead of producing greater satiety, increased fat intake actually increases hunger, so they eat more and gain weight. The key may be to increase protein intake and reduce the fat intake. Some believe that dairy is especially fattening for this type of individual. It is also important to move progressively to eating less frequently so that at most, you eat one full meal a day with much smaller snack-type meals in between large meals.
How much weight is safe to lose quickly?
Most who try LCHF respond positively and lose sometimes unimaginable amounts of weight. The greatest amount reported to me has been 150kg! Billy Tosh in Cape Town set another record by losing 83kg in 28 weeks – no one else I know has come close. These people do it by increasing their fat intakes, cutting sugar to zero grams per day and limiting carbs to less than 25 g/day. To achieve this they have to cut out essentially all processed foods and start cooking for themselves.
For those with abnormal appestat function not corrected by carbohydrate restriction, it may be necessary initially not to eat too much fat and to focus more on increasing protein intake and eating less frequently by practicing some degree of intermittent fasting.
You’re a fan of intermittent fasting?
Yes! The damaging effect of eating carbohydrates is that it produces an insulin response which is exaggerated in those with insulin resistance. Worse, we now know that every time you over-secrete insulin, your body becomes slightly more insulin resistant. Intermittent fasting does the opposite – by reducing the frequency with which you secrete insulin, intermittent fasting reduces the probability that you will develop worsening insulin resistance leading to type 2 diabetes.
What about alcohol?
It’s a toxin, and slows weight loss on LCHF regimens significantly. We say: first lose weight, and reintroduce alcohol in small amounts if you must. LCHF is a fine line. If you don’t fall on the right side of the fat, protein, carb ratio, just one apple, a beer or two glasses of wine will put you on the wrong side, and you won’t enjoy the benefits you should from cutting carbs.
No sweet “cheat” treats at all?
A small piece of dark chocolate is fine, but many people can’t eat just one small piece – like smokers who can’t have one cigarette. The key is to get sugar out the diet. People don’t understand how addictive sugar is, or what it actually is – not just sucrose, the white stuff. If you can get people down to 25g of carbs a day for a few months with no added sugar, the brain no longer searches for sugar. That’s what makes our diet so successful.
And best snacks?
Nuts, biltong, cheese, coconut – I love coconut chips best of all – and full-cream yoghurt.
Are “cheat days” on LCHF really so bad?
Again it depends on your level of insulin resistance and degree of sugar and carbohydrate addiction. The worse your insulin resistance, the more damaging each cheat day will be to long-term health (because each day increases your level of insulin resistance). If you have a sugar addiction the cheat day ensures the addiction will continue. The analogy is to smoking or drinking. No addict can continue indefinitely to smoke or drink “in moderation” or on a cheat-day.
Other myths about LCHF that should be dispelled?
That the diet is necessarily expensive. Our Eat Better South Africa campaign shows it’s possible to LCHF by eating foods that as cheap as the cheap high-carbohydrate, highly processed foods currently the sole option for many of the poorer South African communities.