Posts

Can kids ‘Bant’?

By Tamzyn Murphy

BSc Med(Hons) Human Nutrition and Dietetics, RD

 

We await the verdict of Prof Tim Noakes’ HPCSA trial over a tweet in which he “advised” a mother to wean her child onto LCHF food. In the meantime let’s take a closer look at the evidence regarding Banting and kids…

 

Today’s children are the first generation expected to live shorter lives than their parents [1]. We are seeing more overweight children and adolescents than ever before [2, 3]. And we know that overweight children are likely to grow up into overweight adults, with associated health risks (e.g. heart disease and diabetes) [4]. It is clear that the way most children are eating is not doing their health any favours.

 

If we always do what we’ve always done, we’ll always get what we’ve always got

 

Sickly sweet South African kids

Eating too much sugar is associated with dental caries and increased obesity risk [3]. Both of which are prevalent health concerns amongst South African children.

 

We know that children and adolescents in South Africa, and across the globe, eat more sugar than adults. In fact one study reported that South African children eat about 50g (12.5 teaspoons) of sugar each day, while South African adolescents consume as much as 100g (25 teaspoons) per day [3]. This represents 10-20% of daily calorie consumption [3]. South African adults on the other hand, are thought to be eating approximately 38-51g (9-13 teaspoons) of sugar each day, contributing 10-15% of their calories [3].  The World Health Organisation’s guidelines recommend a maximum of 5% of daily calories from sugar – that’s no more than 7 teaspoons daily from all sources. Reducing or even eliminating our children’s added sugar consumption can only be good for their health.

 

Most medical practitioners and scientists will agree that drastically reducing or even cutting out children’s sources of added sugar can only be good for them. But the question remains, can children safely following a low carbohydrate, high fat (LCHF) diet (popularly known as Banting in South Africa), that’s devoid of starches and wholegrains as well as sugar?

 

Evidence: very LCHF diets in children

Although, very little research has been done on LCHF eating in children, a few studies have shown that overweight  kids and teens (6-18 years of age) who followed a LCHF, containing less than 60g of carbs each day, successfully lost weight, without negatively affecting the levels of fat and cholesterol in their blood [5, 6]. The authors suggest that reducing dietary carbohydrate may be a possible treatment for insulin resistance in children and adolescents.

 

Of note, a very low carbohydrate, ketogenic diet has been successfully used to treat childhood epilepsy for almost a century [7]. A modified version of the Atkin’s diet, also very low in carbohydrates (it only contains 10g), but easier to follow than the ketogenic diet (as, unlike the ketogenic diet it doesn’t also limit calories and protein), has been used successfully for the same purpose for over a decade. Unlike protein and certain fats, dietary carbohydrates are not essential nutrients – our bodies can make them from scratch to use as fuel. So it’s not surprising that both the ketogenic and modified Atkin’s (probably more so than the ketogenic diet, which also limits protein and calories) diets are considered safe when used in conjunction with multivitamin and calcium supplementation [8, 9].

 

“Banting” for children needn’t be very low carb

It’s important to bear in mind that most children who follow a LCHF don’t need to drastically restrict carbohydrates to the ketogenic levels (<60g per day) investigated in the studies discussed above (A LCHF diet typically provides 20-120g of carbohydrate daily or 5-30% of total energy intake). So, while added sugar, starches and grains will be eliminated from their diets, other wholefood sources of carbohydrates won’t be excluded (e.g. dairy, starchy vegetables, nuts, seeds, fruit and even properly prepared legumes).  I recommend that children only restrict their carbohydrates to below 60g under the supervision of a dietitian or knowledgeable medical doctor.

 

Provided that a child consumes the recommended 3 portions of dairy daily and eats enough vegetables, supplementation shouldn’t be any more necessary on this diet than with any other. While I don’t suggest being too restrictive about children’s starchy vegetable, fruit and nut consumption, excluding starches (in the form of grains) and added sugar from children’s diets shouldn’t pose any health risk and will likely come with a host of benefits. Especially considering that these restrictions are done in the context of a diet that emphasises avoiding processed food, while eating REAL, nutrient dense foods.

 

“Banting” for kids simplified

  • Eat real food. Avoid processed food.
  • Eat freely: Avocados, olives, other vegetables, dairy, fish, poultry, meat (including organ meats), eggs, butter, olive oil, coconut oil
  • Eat moderate amounts: Fruit, nuts, seeds, properly prepared legumes (beans, peas, lentils)
  • Exclude: Added sugar (in all its forms), processed food, grains (although it’s likely fine to include limited amounts of the less irritating grains such as oats or quinoa)

 

References 

[1] Olshsky SJ, Passaro DJ, Hershow RC, et al. A Potential Decline in Life Expectancy in the United States in the 21st Century. N Engl J Med 2005; 352:1138-1145 

[2] Gupta N, Goel K, Shah P, Misra A. Childhood Obesity in Developing Countries: Epidemiology, Determinants, and Prevention. Endocrine Reviews. Jan 2012;33(1) 

[3] Steyn N, Temple NJ et al. Evidence to support a food-based dietary guideline on sugar consumption in South Africa. BMC Public Health. 2012;12:502

[4] Singh AS, Mulder C, Twisk JWR, et al. Tracking of childhood overweight into adulthood: a systematic review of the literature. Obesity Reviews. Sep 2008;9(5):474-88 

[5] Gow ML, Ho M, Burrows TL, et al. Impact of dietary macronutrient distribution on BMI and cardiometabolic outcomes in overweight and obesechildren and adolescents: a systematic review. Nutr Rev. 2014 Jul;72(7):453-70. 

[6] Sondike SB, Copperman N, Jacobson MS. Effects of a low-carbohydrate diet on weight loss and cardiovascular risk factor in overweight adolescents. J Pediatr. 2003 Mar;142(3):253-8. 

[7] NICUS. The Ketogenic Diet…Fa(c)t or fiction? 2007

[8] Tonekaboni SH, Mostaghimi P, Mirmiran P, et al. Efficacy of the Atkins diet as therapy for intractable epilepsy in children. Arch Iran Med. 2010 Nov;13(6):492-7. 

[9] Suo C, Liao J, Lu X, et al. Efficacy and safety of the ketogenic diet in Chinese children. Seizure. 2013 Apr;22(3):174-8. 

Diets that do and diets that don’t: Part 2 – The Paleo Diet

By Tamzyn Murphy

BSc Med(Hons) Human Nutrition and Dietetics, RD

 

The Paleo diet, founded by researcher Loren Cordain (PhD), is based on what our caveman ancestors ate. It includes only the foods we’ve eaten for most of human history; which we’ve evolved to eat. Like Atkins, Paleo is a low carb, moderate protein, high fat diet. You’re allowed as much meat, fish, poultry, eggs, natural fat (e.g. butter, olive oil, avocado) and non-starchy vegetables as you like. Unlike Atkins, Paleo allows any other foods that our caveman ancestors ate, like any root vegetables, nuts, seeds and fruit.  We only became dependent on farmed foods, like grains, legumes (beans, peas, lentils) and dairy, relatively recently – less than 500 generations ago – with the advent of agriculture. So our genes haven’t had much time to adapt to problem compounds in these foods, theoretically causing inflammation and weight gain.

Indeed, grains and legumes contain anti-nutrients (like lectin and gluten) which interfere with nutrient absorption, irritate intestinal lining (promoting leaky gut) and yield other toxic effects. Cereal grains, particularly wheat, are the worst.[i] So there’s a case to be made for limiting or even eliminating them. But legumes’ anti-nutrients are largely inactivated by cooking at high temperatures, which makes them relatively safe[ii]. Plus legumes contain numerous beneficial compounds.[iii] They’re also are an important protein source – particularly important for vegetarians, vegans and the poor; not to mention ethical and environment-friendly meat-replacements. There’s no evidence that legumes increase weight gain. Research shows that dairy doesn’t have inflammatory[iv] or weight promoting effects[v]. In fact it may do the opposite.

So, the theory behind Paleo is sound – eat whole, unprocessed food as much as possible. But including moderate amounts of dairy and legumes may offer more benefits than risks. Paleo loses points on the expense-front, and due to the lack of dairy you might want to supplement with calcium and vitamin D, unless you’re getting plenty of other calcium rich foods and enough sunshine.

 

References

[i] Cordain L. Cereal Grains: Humanity’s Double Edged Sword. Simopoulos AP (ed): Evolutionary Aspects of Nutrition and Health.Diet, Exercise, Genetics and Chronic Disease. World Rev Nutr Diet. Basel, Karger, 1999;84:19-73

[ii] Pusztai A, Grant G. Assessment of lectin inactivation by heat and digestion. Methods Mol Med. 1998;9:505-14 

[iii] Bouchenak M, Lamri-Senhadji M. Nutritional quality of legumes, and their role in cardiometabolic risk prevention: a review. J Med Food. 2013 Mar;16(3):185-98 

[iv] Labonté MÈ, Couture P, et al. Impact of dairy products on biomarkers of inflammation: a systematic review of randomized controlled nutritional intervention studies in overweight and obese adults. Am J Clin Nutr. 2013 Apr;97(4):706-17 

[v] Abargouei AS, Janghorbani M,  et al. Effect of dairy consumption on weight and body composition in adults: a systematic review and meta-analysis of randomized controlled clinical trials. Int J Obes (Lond). 2012 Dec;36(12):1485-93 

The first Prof Tim Noakes ‘Banting’ lecture that I ever attended

“At any given moment there is an orthodoxy, a body of ideas which it is assumed that all right-thinking people will accept without question… A genuinely unfashionable opinion is almost never given a fair hearing, either in the popular press or in the highbrow periodicals.” – George Orwell, Animal Farm, 1945

 

By Tamzyn Murphy Campbell

BSc, BSc Med(Hons) Human Nutrition and Dietetics, RD

 

It’s January 2013. Waiting for his talk to start, in his grey suit and Nike trainers, Professor Tim Noakes looks far trimmer than when I saw him last, five years ago at a talk on University of Cape Town’s medical campus. His weight loss should come as no surprise though, considering he’s been following his own advice, avoiding carbohydrates, which he claims is the key to solving our global obesity epidemic.

“I’ve been declared officially mad by my faculty,” begins Prof Noakes. Despite being shunned by his peers for his unconventional dietary advice, Prof Noakes appears happy and relaxed and impossible not to like with a big friendly smile stretched across his face. Maybe it’s insanity that’s got him so at ease in the face of scorn. Or perhaps he’s just calmly confident that he’s right. As he explains later in the talk, he has acted ethically by correcting the misconceptions responsible for our ill health as soon as he became aware of them.

Let me walk you through Prof Noake’s argument and then you decide on which side of the nutritional fence you’d like to sit.

 

WHY THE CONTROVERSY?

It’s accepted as fact that we get fat because we eat too much and exercise too little: the twin sins of gluttony and sloth. The prevailing belief is that a high fat intake promotes weight gain and heart disease. Authorities say that saturated fat (mainly from animal-derived food sources) raises cholesterol, which in turn clogs our arteries leading to heart disease. This knowledge stems from the Seven Country Study, published in 1963 and conducted by a scientist called Ancel Keys who found that men in countries with diets high in saturated fat suffered from more heart disease. What Keys failed to mention was that countries that didn’t support this finding were left out of his study. He also failed to report that heart disease incidence happened to increase with a higher sugar intake.

Flying in the face of what we accept as the fundamental truths of nutrition, Prof Noakes declares that fat doesn’t raise cholesterol and cause heart disease nor promote weight gain and we certainly aren’t getting fat because we’re eating too much and exercising too little. He doesn’t expect us to blindly believe him though, presenting us with statistics and cutting-edge scientific intervention and review studies that back up what he has to say. This unconventional opinion, especially from such a well-published and respected scientist, has thrown the South African scientific and medical community into a furor. But according to Prof Noakes, the most outraged are those scientists who are receiving funding from the food industry.

 

MONEY, POLITICS & CORRUPTION

“It is difficult to get a man to understand something, when his salary depends on his not understanding it,” quotes Prof Noakes when a member of the audience asks how we can possibly believe him when so many scientists disagree. The food industry’s lifeblood is tasty and addictive food and beverages, packed full of carbohydrates and sugar. According to Prof Noakes, if South Africa’s university departments who rely on industry funding – such as cardiology, pharmacology or nutrition – were to speak out against carbohydrates and sugar (or the efficacy of prescription medication in the case of pharmacology faculties) then their research funding would be pulled and their departments may as well shut down.

Prof Noakes says that a researcher who acts as industry’s mouthpiece stands to gain a lot of money and exposure: “These companies will support any researcher that will stand up here and punt exercise to lose weight [in order to avoid recommendations that’ll reduce their sales]”. He goes on to say that industry-funded study results are biased, misleading and often downright wrong. “Ninety-five percent of nutrition advice is based on association studies,” Prof Noakes explains, “and 85% of association studies are wrong.” Association studies show how factors change in relation to each other but are unable to show that one factor causes the other. For example, in Ancel Keys’ Seven Country Study heart disease increased in countries that had higher saturated fat consumption. This doesn’t mean that saturated fat caused the increased heart disease. Other factors could be to blame. As it turns out, sugar consumption happened to increase along with saturated fat in these countries and could possibly explain the increased heart disease risk.

According to Prof Noakes, the two biggest funders of US nutrition research, the National Institute of Health and the US government, will only fund studies that show that high carbohydrate intake is healthy.  This is following a decision made by the US senate, in 1977, to fund corn, soya and vegetable oil agriculture, and the development of US dietary guidelines in the same year recommending that Americans get 50–60% of their total daily energy from carbohydrates, while limiting dietary fat and cholesterol. Prof Noakes explains that these decisions were made to be in line with what grain farmers and the major industry-controlling food companies wanted.

 

CARBS MAKE US FAT

Prof Noakes explains that we’ve genetically evolved to eat a low carbohydrate diet, saying that we don’t actually need to eat carbohydrate to survive, whereas protein and fat are essential for survival. Also, it appears that our calorie and carbohydrate consumption has increased concurrently with obesity over the decades, but our fat intake has remained relatively constant. This implies that it’s not the fat that’s to blame for our ballooning waistlines.

So if Prof Noakes is right and carbohydrates really are to blame, then how do they do it? Prof Noakes claims that carbohydrates upset the body’s natural energy-regulation ability – your homeostat that’s supposed to balance your calories consumed with the calories you burn (calories in versus calories out).  Eating more carbs these days means we’re getting lots of glucose into our bloodstreams. Our bodies have to secrete more of the hormone insulin to keep these potentially damaging glucose levels under control. And as it turns out, insulin promotes fat storage and makes us eat more.

Prof Noakes says that insulin promotes liver triglyceride (fat) production and storage, leading to metabolic problems including diabetes and obesity.[1] Insulin also encourages fat storage in adipose tissue (fat stores), particularly in those who’re genetically predisposed, thereby promoting weight gain. According to Prof Noakes, those who are naturally carbohydrate resistant consistently oversecrete insulin in response to eating carbs. This consistently high insulin means that dietary carbs are continuously being converted to fat and stored away for a rainy day.

All of this carbohydrate conversion and fat storage leaves little energy available to your cells, so you quickly get hungry again, craving a quick-release energy source like, you guessed it, carbohydrates. And so the vicious cycle begins. Prof Noakes says that since he’s been on his low-carb diet he only gets hungry every 16–24 hours. To make matters worse it turns out that carbs are addictive. They temporarily boost the pleasure chemicals in your brain and your mood. Then they drop again, leaving you craving your next carbohydrate fix. “Addictive food choices cause obesity in those with insulin resistance,” says Prof Noakes, “it took me 14 months to stop adding sugar to my tea and coffee but it’ll take me one day to go back.”

 

SOME AND NOT OTHERS

Why then do only some of us get fat on a high-carbohydrate diet, while others can eat what they like and stay lean? Prof Noakes explains that if you’re genetically prone to carbohydrate or insulin resistance, as most of us are, then your body goes into fat production and storage mode in response to carbohydrates and insulin, resulting in constant hunger, inactivity and, consequently, weight gain. If you’re one of the lucky few who can eat what you like and stay lean then your body is better able to utilise carbohydrates as a fuel source rather than storing it as fat in response to insulin. Prof Noakes says that the amount of dietary carbohydrates different people can tolerate varies. “The difference between being lean, as I am, or fat is 25g of carbohydrates,” claims Prof Noakes. This amount is very low. Most people will be able to lose excess fat and maintain a stable healthy weight at somewhere between 20 and 120g of carbohydrates daily.

Prof Noakes also implicates carbohydrates in the dreaded middle-age spread: “As we get older we get more carbohydrate resistant”. So if you could eat what you liked in your youth but are now finding that a spare tire has settled around your middle, cutting all starches and sugars may help you maintain a svelte shape.

 

CARBS MAKE US SICK

“Eighty percent of diseases are caused by nutrition.” According to Prof Noakes, carbohydrates aren’t just to blame for the obesity epidemic but also for the chronic diseases that plague modern society. “There’s one cause [carbohydrates], one treatment [cutting carbohydrates] for all conditions,” reveals Prof Noakes – listing diabetes, cardiovascular disease, metabolic syndrome, high blood pressure, gout, cancer and even Alzheimer’s. Prof Noakes calls insulin the aging hormone, saying, “Alzheimer’s is caused by high insulin” and “cancer, specifically colon and breast cancer, is driven by high insulin”.

Prof Noakes addresses critics’ main arrow in the quiver against a low-carb diet, being that its high fat content increases heart disease risk. It turns out that well-designed, up-to-date research indicates that saturated fat appears to have no effect on death rates[2] and heart disease.[3] A higher carbohydrate intake, on the other hand, increases all the heart disease risk factors.[4] It boosts levels of fats, bad cholesterol (small LDL), insulin and glucose in the blood, while reducing the good cholesterol and boosting your belly.

“If you are eating these [starches] then that’s what you will die from,” Prof Noakes acknowledges with a sad smile.

 

TIPS

If you struggle with your weight, get hungry every three hours or so and dread exercise then Prof Noakes explains that you’re probably carbohydrate resistant and can benefit from cutting down on dietary carbohydrates. His advice? “If it doesn’t occur in nature, don’t eat it.”

A low-carbohydrate diet is typically high in fat and moderate in protein. You’ll need to cut out all grains, sugar and trans fats. Stick to meat, poultry, fish, eggs, vegetables (like spinach, broccoli, tomatoes, mushrooms, lettuce, cucumber, carrots), nuts, avocado pear and olive oil. Prof Noakes warns to stay away from most other vegetable oils though, specifically those high in pro-inflammatory and blood-clotting omega-6 fats like sunflower and corn oils. Full-cream or low-fat dairy products are acceptable in moderation. Depending on how much carbohydrate you can tolerate before you start to balloon, you may even be able to squeeze in a few legumes, a touch of starchy vegetables and low-sugar fruit (like berries and apples) – though it’s probably best to tread with caution when trying these food items on your low-carb diet. Prof Noakes cautions to watch out for sweet beverages, advising sticking to unsweetened water, tea and coffee. And he suggests that most people could benefit from supplementation with omega 3 fats and vitamin D (particularly if you have mid to low range vitamin D levels like he has), due to the strong scientific evidence supporting their use.

 

References include

[1] Petersen KF, Dufour S, et al. The role of skeletal muscle resistance in the pathogenesis of metabolic syndrome. PNAS. Jul 2007;104(31):12587-94 http://www.pnas.org/content/104/31/12587.full.pdf+html

[2] Schoenaker DA, Toeller M, et al. Dietary saturated fat and fibre and risk of cardiovascular disease and all-cause mortality among type 1 diabetic patients: the EURODIAB Prospective Complications Study. Diabetologia. 2012 Aug;55(8):2132-41 http://www.ncbi.nlm.nih.gov/pubmed/22526612

[3] Howard BV, Van Horn L, et al. Low-fat dietary pattern and risk of cardiovascular disease: the Women’s Health Initiative Randomized Controlled Dietary Modification Trial. JAMA. Feb 2006;295(6):655-66. http://www.ncbi.nlm.nih.gov/pubmed/16467234

[4] Siri-Tarino et al. Saturated fat, carbohydrate and cardiovascular disease. Am J Clin Nutr. Mar 2010;91(3):502-9 http://ajcn.nutrition.org/content/91/3/502.full.pdf+html

Side effects of low carbohydrate high fat (LCHF) eating

By Tamzyn Murphy Campbell

BSc, BSc Med(Hons) Human Nutrition and Dietetics, RD

 

Many people experience certain common side effects when following low carbohydrate high fat (LCHF). These include:

  1. Keto “flu”: during the first week of starting LCHF some people experience aches and pains, headaches, lethargy, nausea, brain fog and/or irritability.
  2. Constipation
  3. Fatigue/lethargy
  4. Muscle aches/cramps
  5. Headaches
  6. Signs of low blood pressure, including heart palpitations, dizziness and nausea.

The good news is that the root cause of these symptoms is the same and completely rectifiable.

 

What’s behind the symptoms?

When you are eating a conventional high carbohydrate diet, your body is producing quite a lot of insulin. Insulin is produced by the pancreatic beta cells in response to glucose or “sugar” entering the bloodstream after digestion of a carbohydrate-containing food or beverage. Insulin’s job is to remove “sugar” from the bloodstream and put it into the cells, where it’s turned into energy or stored. One of the side effects of insulin is to reduce the kidneys’ excretion of water and certain electrolytes or minerals (namely, sodium or ‘salt’, magnesium and potassium) [1-3].

Conversely, when you eat a low carbohydrate diet the amount of insulin that your pancreas produces is dramatically reduced, as there’s much less carbohydrate entering the blood stream from your diet. The lower insulin level results in increased excretion of water, sodium, magnesium and potassium from the kidneys.  This loss of fluid often lowers blood pressure and can cause dehydration if the fluid is not replaced by drinking more. The resulting symptoms can include headaches and symptoms of low blood pressure, including fatigue/lethargy, heart palpitations, dizziness and nausea. The loss of sodium, potassium and magnesium can cause muscle aches, pains and cramps, as well as irritability. [1]

 

How to fix it

  1. Drink plenty of fluids (to thirst)
  2. Add salt to your food
  3. Drink a cup of bone broth every day
  4. Take a magnesium supplement, which provides 400 mg of elemental magnesium daily. Choose a supplement that contains magnesium in the form of a magnesium chelate (elemental magnesium bound to an amino acid), such as magnesium glycinate, for optimal absorption.

 

Important note: Should drinking more fluids, consuming more salt, drinking bone broth and taking a magnesium supplement not improve your symptoms, it is important that you see your doctor as soon as possible.

 

References

  1. Volek JS and Phinney SD. The art and science of low carbohydrate living. 2011
  2. DeFronzo RA. The effect of insulin on renal sodium metabolism. A review with clinical implications. 1981 Sep;21(3):165-71.
  3. Quiñones-Galvan A, Ferrannini E. Renal effects of insulin in man. J Nephrol. 1997 Jul-Aug;10(4):188-91.