Why are there so many diets?

There are so many diets out there – all claiming to give the best results, and having strong proponents.  Many are driven by business interests – you have to buy supplements and pills and special foods.  All diets have some benefits, and all will result in some weight loss.  The problem is whether they are sustainable and healthy for you.  They may be extreme, or expensive, or make you feel bad, or may even negatively affect your health in the long term.  Some diets may also be bad for the environment – but more of that later.

ALSO READ : Turning the Tide – Dealing with the main lifestyle-related conditions in South Africa (Part 3)

The Ketogenic Diet (also known as Banting).

One of the most publicised and popular in South Africa is the Banting Diet.  Professor Tim Noakes is intimately connected with this diet and has been its most famous proponent.  A well known figure from Comrades, but also for his world-renowned Sports Medicine research, he has been much in the spotlight over the last few years for his controversial advice promoting a ketogenic diet even for children.  He has been a strong proponent of “real foods” which promotes a diet very low in carbohydrates but high in animal proteins and saturated fats.  This advice undermines long held beliefs that excess saturated fat in the diet is harmful – being at the core of heart disease and atherosclerosis.  His Banting movement has come with a plethora of books and marketing strategies.  You will find many foods with “Banting friendly” labels, but also “low-carb”, “real food”, “wheat-free” and “gluten-free”, which are often associated with the Banting lifestyle.

Tim Noakes is certainly not the originator of the concept.  Dr Robert Atkins, an internist and cardiologist developed the diet in the 1970’s.  It promoted a diet high in animal proteins and fats and low in carbohydrates as found in breads, pasta, fruits, legumes and refine sugar.  His ideas have swept the medical world, popularised on the media and with his many books and articles.  It was first promoted as a weight loss diet, but also became popular for control of diabetes and insulin resistance.  Some proponents even claimed it helped with the control of certain cancers, although that claim has fallen by the wayside.  Its most notable benefit is in controlling resistant epilepsy, but not without significant complications like constipation, reflux, excessive weight loss and kidney stones, especially if not adequately hydrated.

How does the ketogenic diet work?  Normal physiology uses glucose to power the cell “engines” and provide energy for all the physiological functions involved in daily life. 

By drastically limiting glucose intake in the form of carbohydrates, the body is forced to burn fat as the main energy source, and this results in the production of ketones.  Ketones have a side effect on reducing your appetite – apart from giving you bad breath and making you feel unwell to begin with.

Because there is so little carbohydrate ingested, insulin is not needed to facilitate absorption of glucose into the cells; blood sugar levels become lower; long term HbA1c (a marker of diabetic control) levels drop and doctors are delighted that diabetes seems to be under control.  However this doesn’t deal with the underlying insulin resistance, because if you give a patient on a ketogenic diet some carbohydrate, the blood sugar levels with go screaming up.  We have dealt with the cause of insulin resistance in other articles.

Most of the studies looking at the benefits of the ketogenic diet last only a few months.  I came across one study claiming to be long term study of consequences of the ketogenic diet and that was only for 24 weeks – less than 6 months.  Long term studies should be over years – 5-10 years with large numbers of participants.  Here are some of the complications found with longer term use of the ketogenic diet:   .

Studies lasting up to 15 years have shown increase in all-cause mortality from such conditions as heart disease, cancer, and complications of diabetes.  See the this article.

An important contribution of high-carbohydrate foods, such as fruits, whole-grains and legumes, is the ingestion of adequate amounts of dietary fibre.  This fibre is essential for gut health, and particularly gut microbe nutrition.  A healthy gut microbiome contributes so much to normal bowel function, but also a healthy immune system, cardiovascular health and even mental well-being.  It has been reported that up to 80% of neurotransmitters that keep us mentally happy are produced by gut micro-organisms rather than brain cells.  Dietary fibre is also important in reducing the risk of bowel cancer by neutralising toxins, and increasing bowel passage time, thus the time of gut exposure to carcinogens.

ALSO READ : Turning the Tide – Dealing with the main lifestyle-related conditions in South Africa (Part 2)

What are some of the other negatives about the ketogenic diet?  Already the factory farming industry is a major contributor to greenhouse gases on our planet, in particular methane.  As animal products are a large part of the ketogenic diet, if more people were to move to this diet, it would increase the climate change effects even more.

Most people who really take the trouble to see how domestic animals and poultry are farmed these days for the food industry would be disgusted at the inhumane conditions found in these factory farms.  Ethics dictates that supporting this kind of industry is demeaning to humanity.  Modern farming practices are far removed from the romantic notions of small-scale farmers who allowed their animals to roam over the farm and in the pastures in times past.

There is no doubt that the ketogenic diet is expensive.  Good quality meat/poultry/fish is only really affordable by more affluent people.  In reality it is far cheaper to buy a variety of in-season fruits and vegetables, whole grains and legumes.  However in many countries, significant government subsidies provide cheap inputs into the meat industry and grain farming which makes sugar-laden, unhealthy fast-foods cheaper, adversely affecting consumption of healthy plant-based foods amongst people with low income.  Some health interest groups are actively lobbying government agencies to shift subsidies to more healthy food alternatives in the USA.

What are some of the positive contributions by promotors of the ketogenic diet?

There is no doubt that highly refined carbohydrates are not good for you.  Sugar is far too prevalent in processed foods.  Far too much of the food generally ingested is unnatural, thus the emphasis on real food is beneficial.  I don’t have an argument against the need to cut refined carbohydrates from the diet.  The big problem I have with the ketogenic advocates is removing most dietary sources of carbohydrates, from the main food groups such as starchy fruits, grains and legumes.

The longest-living population groups around the planet emphasise fruits, vegetables, whole grains and particularly legumes in their diets.  They seldom have problems with diabetes, gastro-intestinal complains, auto-immune diseases, Alzheimer’s Disease, heart disease and cancers.

If a high carbohydrate diet was so bad for you, these people who eat a high carbohydrate diet would be in trouble.

There is no doubt that in the short term, people lose weight on a ketogenic diet.  But this is also a feature of almost all diets.  It serves to focus people’s attention on their lifestyle, and helps them to think about what they are doing to their bodies.  This is good.  We all need a wake-up call from time to time to reassess where our lifestyle is directing us in the long term.

Diabetics in the short term find a ketogenic diet reduces blood sugar, high insulin levels and the need for diabetic medications.  Unfortunately as mentioned above the ketogenic diet has long term adverse consequences which negates the short term benefits.

Conclusion:

If you feel the need to improve your health, and Banting is the first option that you meet, it is good to recognise that major changes in your diet may be needed to rejuvenate your health.

In the short term there may be benefits from the Banting diet, but you would do better on a whole-food, plant-based diet if you are really wanting to gain general health in terms of long-term diabetes control, reduction of risk of heart disease, and even reversal of arterial narrowing, reduction of risk of cerebra-vascular disease, reduction in the risk of many cancers, natural weight loss,  better bowel function, greater energy and quicker recovery times for sportspeople, clearer brain function and reduced risk of Alzheimer’s Disease and other dementias, and general reduction of chronic inflammation.

To a week re-evaluating your diet, and moving more to a plant-friendly diet for health and wholeness.

Next week we will look at the “Mediterranean” diet.

Dave Glass

Dr David Glass graduated from UCT in 1975. He spent the next 12 years working at a mission hospital in Lesotho, where much of his work involved health education and interventions to improve health, aside from the normal busy clinical work of an under-resourced mission hospital.

He returned to UCT in 1990 to specialise in obstetrics/gynaecology and then moved to the South Coast where he had the privilege of, amongst other things, ushering 7000 babies into the world. He no longer delivers babies but is still very clinically active in gynaecology.

An old passion, preventive health care, has now replaced the obstetrics side of his work. He is eager to share insights he has gathered over the years on how to prevent and reverse so many of the modern scourges of lifestyle – obesity, diabetes, ischaemic heart disease, high blood pressure, arthritis, common cancers, etc.

He is a family man, with a supportive wife, and two grown children, and four beautiful grandchildren. His hobbies include walking, cycling, vegetable gardening, bird-watching, travelling and writing. He is active in community health outreach and deeply involved in church activities. He enjoys teaching and sharing information.

HAVE YOUR SAY

Like our Facebook page, follow us on Twitter and Instagram