Low-Carb Eating. What’s it all About?
In recent years, there has been much talked about in terms of low-carb eating and its reported benefits. In the last 4 years, 35 plus papers have been published on low-carb diets: Comparing them to each other, comparing them to high-carb/ low-fat diets and so on. Some have looked at weight loss and others at blood serum ‘general health biomarkers’ (triglycerides, HDL, LDL, cholesterol, and C-reactive protein – an indicator of inflammation in the body). The results are very clear (in the more rigidly controlled studies). Low-fat diets perform as well as low-fat/ higher carb ones on every parameter.
In the majority of cases, they actually perform better in terms of weight loss (and more importantly, maintenance of this loss). HDL levels (good cholesterol) are higher and Triglyceride levels (which is as important a risk factor, if not more so, than cholesterol for heart disease) are nearly always lower for low-carb regimens, and moreover, C-reactive protein (only recently studied more in depth) always responds better with low-carb. The latter is a slap in the face for all those anti-low-carb individuals, as C-reactive protein is a very effective indicator of general inflammation in the body, something which on the higher end of the scale is correlated with a range of chronic diseases reducing longevity, from obesity to heart disease (Arrigo, 2007; Bowden, 2010; Freedman, 2001).
Low-carb (low-carbohydrate) nutrition is something which is central to both my life (I live and breathe low-carb) and also to that of many of my clients: 90% of my clients eat low-carb as it creates a lean and strong physique in both the long and short terms, increases energy levels and even enhances performance in the long term. This being said, everyone is different in terms of activity level, hormone profile and metabolic differences. Low-carb is not one size fits all and there are individuals who work best and indeed become leaner from consuming a diet of 40% carbohydrates and there are those that get better results from a diet of 20% of their caloric intake coming from carbohydrates.
Before we get going, it is important to clarify what exactly low-carb is and what everyone is shouting about. The average person’s diet in the Western World (France, the UK, US combined) gleans energy (calorie intake) from somewhere between 50 and 65% carbohydrates, the rest coming from fat and protein (all three of these are macronutrients). The typical food pyramid that we have been taught in schools and indeed many health practitioners still advise adhering to, suggests consuming around 50% of your calorie intake as carbohydrates. The fact that many of these carbohydrate sources are from cereal and grain crops and processed foods is one of, if not the main source of the myriad rising illnesses in society today (heart disease, osteoporosis, obesity, to name a few), argues Jonny Bowden, in ‘Living Low Carb’ (2010).
One person’s “hot” is another person’s “warm”. There are no objective boundaries for these two terms, much the same as the much-banded-around term “low-carb”. On Dr Atkins’ Atkins Diet only 20g of carbohydrates is permitted for a large part of it, per day. On the other end of the low-carb spectrum, Barry Sears’ “The Zone” advises up to 40% of calories from carbohydrates. If you are a conventionally trained nutritionist or dietician, or indeed a government agency, then anything below 65% of calories from carbohydrates will be “low-carb”. Likewise there are those that believe that consuming more than 10% of your calories from protein is going to cause kidney failure, or if you believe that eating more than a bare minimum of fat in your diet will lead to heart disease. These beliefs need to be reexamined as indeed they are not true, yet much-pushed ideas in the general media. As much as I could spend hours picking through the pros and cons of each low-carb diet and reviewing each one, there are a few fundamentals I want to get to grips with today. As much as we could pick holes in all low-carb diets (some a lot more than others), we must understand two things:
- A Diet is a Diet. Its Effects are Often Short-lived.
I am careful with the use of this word – ‘diet’. For instance, at my Bootcamps, I never use the word in terms of a dramatic, short-term way of eating (only when we make use of perhaps a week’s ‘Bootcamp’ style kick start). The essence of my PowerPack eating plan is to encourage a way of eating that both sets up one’s body to burn fat optimally whilst gaining strength and fitness (amongst other things) and yet is realistic and sustainable in the long term also. It is NOT a diet per se. A diet in its very essence, generally means a short term drop in weight. This weight is not only fat loss; it is often accompanied by muscle and water loss as well. So as time goes on, sustaining results becomes harder and harder. If we are not gaining lean muscle mass (muscle weight in proportion to fat weight) alongside the fat loss, then we lose out on the thermogenic benefits extra muscle gives us. The more muscle we have the more fat we burn day in day out. Likewise, the more hydrated we are, the more efficient we are at burning fat. The very nature of a diet is why I rarely use them for my clients. I prefer to educate and change the way people eat, make choices in the supermarket, restaurant and from the take-away menu. I look upon my PowerPack eating plan that Bootcampers use, as a ‘WAY OF EATING FOR BOOTCAMP AND FOR LIFE’.
- Not all Calories and Carbs are Created Equal.
Rather than worry about how many of our calories are coming from which food source, we should be concerned more about the quality and type of food we eat. As not all fat is created equal and all protein is far from equal, likewise not all carbohydrates are either. Low-carb does not mean no-carb. Carbohydrates come from various sources, not just from cereals and grains (such as pasta, bread, rice). Non-starchy vegetables, such as broccoli, contain around 5g per 100, of carbohydrates. Fruits on average contain 13% carbohydrate. Other sources, such as starchy root vegetables, beans and nuts and seeds, contain between 7 and 20g per 100, of carbohydrates. In stark contrast however, cereal grains on average are 72% carbohydrate. Many whole grains and legumes are poor sources of vitamins and minerals. A diet (way of eating!) that is slanted too heavily towards grains and legumes (at the expense of fruits, vegetables, fish and lean meats) will lead to vitamin and mineral deficiencies (as of course will a diet leaning too heavily towards only meat and fish for example).
Humans are omnivores. We have evolved to survive very well on a range of diets and macronutrient percentages. In the 1920s, a researcher named Weston Price investigated 16 of the surviving hunter-gatherer societies still eating their native diets. Needless to say, he found excellent health amongst them all. They ate a wide variety of calories, from a wide variety of sources. The Bantu from South Africa ate a high proportion of carbohydrates, the Inuits of Greenland ate very high fat diets (interestingly the average Inuit diet consists of 85% fat and 15% protein and negligible carbohydrates, yet Inuit are known to be able to run 50km per day beside their sleds) and the Trobriand Islanders ate a very high-protein diet. Whether these hunter-gatherers ate mainly plants, fish, meat, or even fresh cream; they all had one thing in common: They didn’t eat processed foods, they didn’t eat sugar and they didn’t eat grain crops.
As noted in his book ‘The Paleo Diet”, Loren Cordain (2011) says “grains and legumes contain “antinutrients” – chemicals that actually prevent your body from absorbing the proper nutrients and can damage the gastrointestinal and immune systems. Too many grains and legumes can disrupt the acid balance in the kidneys, and can contribute to the loss of muscle mass and bone mineral content with aging.” Cordain goes on to discuss how the whole grains of old, which admittedly were reasonably rich in fibre and had reasonably efficacious levels of micronutrients (I said reasonably, not high), have been replaced in the last century with a more highly-processed, rolled alternative, which does a good job at spiking insulin levels and has been practically leached of all health benefits. Although there are a couple of draw-backs to “The Paleo Diet” (namely his take on the cholesterol-heart disease hypothesis and his devaluation of sweet potatoes and butters and creams – another blog I’m afraid…!) the basic premise is one which I abide by in my personal practice and in my Personal Training.
Following the tenets of nutritional anthropology, DNA evidence suggests that our human genome (or DNA) has changed only 0.02 (that’s just one fiftieth of one percent) in the last 40,000 years (Cordain, 2011). Therefore, our digestive, hormonal and immune systems (which are identical to that of our caveman ancestors) are plainly unsuited to today’s dietary staples: dairy, fatty salted meats, processed foods and refined sugar. Our DNA has changed 0.02 percent, yet our diet has changed up to 75% (depending on the individual of course). You don’t need to be a mathematician to see the discrepancy here. In general (and I realise this isn’t always possible, but as close as is possible) Paddy’s Four Food Rules are eat only if you could HUNT, GATHER, FISH or PLUCK it, it’s good to eat! This way, you are eating what your body is happy eating and was designed to eat (has evolved for).
However, there are health-care professionals and trainers who have gone too far in this direction to suggest that calorie consumption does not matter at all. Of course it does. If you are consuming regularly too many calories, you will start to store this excess energy as fat. On the other side of this coin, it is not always so simple (as there are other restrictions to fat loss which make a simple calories in vs. calories out equation often limited – this is why I like to perform a Biosignature Hormone Modulation on all of my one-to-one clients, to lose fat precisely and effectively, according to one’s individual hormone profile). However, it goes without saying that fat cannot be lost if at some stage there is not a calorie deficit. The reason for this misleading and contradicting advice is because the health and fitness industry is both extremely faddish and reactive, rather than proactive. The very 90′s way of ‘the only way to lose fat is calorie counting’ has been hijacked by low calorie, low fat, high sugar food manufacturers who want the unsuspecting public to believe that a 300 calorie of a no-named (!) sweet tasting breakfast cereal is a better breakfast choice for your health and body composition than 300 calories from a lean vegetable omelette. As long as the net calories are the same, then it is equal yes? No, absolutely not! This is just good marketing (and that’s being generous). This is my big bugbear with a certain diet company, naming no names, that has two words and both start with ‘W’! Macronutrients (fats, carbs and proteins) have a profound impact on hormonal balance and metabolic health.
Which leads to me to…
Why Eating Low-Carb Works (The Science)
Bear With Me on This… Insulin control is the primary reason that low-carb diets work and the reason that eating low-carb in the long term is effective. When an individual with normal insulin response (an insulin-resistant individual has difficulty becoming lean unless this is resolved) ingests carbohydrate, the carbohydrate is broken down as glucose. The hormone insulin is then released. Insulin facilitates glucose uptake into the body’s muscles and liver where it can be stored as glycogen or burned as energy (or fuel) or it stores it as fat. Insulin is the main culprit for fat storage, as it is the hormone responsible for storing excess glucose as fat. Glucagon (insulin’s counterpart or enemy, not sure which is more appropriate) helps mobilise fat stores, as it is responsible for the initial breaking down of glycogen. This happens in response to either the presence of adrenaline, lactic acid (another plus in the anaerobic workout column!), increase in dietary protein and a decline in blood sugar (low insulin). If there is a restriction on carbohydrates, i.e. the body has a shortage of glucose, contrary to popular belief, the body does not run out of energy. For maybe one or two weeks, performance and energy levels go down as the body becomes accustomed to this new way of eating. However, what happens when the body doesn’t have enough carbohydrates to keep up the body’s demand for energy? Something called gluconeogenesis (the creation of new sugar from non-carbohydrate sources) results in using other sources (using the glycerol molecule in triglycerides – sugars from fats – and transferring certain amino acids – protein – to sugar). If carbohydrates are sufficiently reduced, (for example on a starting low-carb kick-start eating plan) then the majority of energy comes from ketones by a process called beta-oxidation. This oft-demonised bi-product of fat breakdown is actually used very well by the body with no side effects to the brain, heart, body and already healthy kidneys (again that is another blog I fear!). Despite common belief, they are not dangerous and are a natural part of fat metabolism.
Basically, if your body doesn’t have enough sugar coming in to burn as fuel (from carbohydrate or alcohol sources), it has to make its own; mostly from dietary fat and certain protein sources, or thereafter (if energy is not sufficient from these first two) the body’s fat stores (hence the ketones).
The evidence and science behind the health benefits of living a low-carb life and eating low carb in both the short and long term, is irrefutable. If this is the case, why is everyone not eating low-carb? This my dear friends, is a question for another day (as I just caught a peek at the word count!) Next time I may also talk about the myths of low-carb diets and why they are incorrect (the body needs carbs, low-carb causes calcium loss and bone loss, low-carb is bad for your kidneys). Enough of my low-carb ranting for one night (there’s plenty more where this came from). Until next time…
Arrigo, D; Low-Fat versus Low-carb. What Really Works? Diabetes Forecast. 2007. 60 (7). 16-18.
Bowden, J. Living Low Carb. (New York: Sterling, 2010).Gotto, A.M. Triglyceride: The Forgotten Risk Factor. Circulation. 1998. 97 (22), 1027-1028.
Cordain, L. The Paleo Diet. (New Jersey: Wiley, 2011).
Freedman, R. Popular Diets: A Scientific Review. Obesity Research. 2001. 9, 5-17.
Layman, D.K. A Reduced Ratio of Dietary Carbohydrate to Protein Improves Body Composition and Blood Lipid Profiles During Weight Loss in Adult Women. Journal of Nutrition. 2003. 133 (2), 411-417.