LCHF and IF for the female endurance athlete (IMHO).

Following on from the couple of blogs I wrote about Dan’s LCHF athlete lifestyle, I got a lot of messages from women regarding my opinion of it for the female endurance athlete. Great question, especially as – if you look at social media – there are nutritionists who warn against the danger of LCHF (and intermittent fasting) for women, to the point that the blanket statement is that it is harmful and not to be undertaken. Whilst it is hard to be objective in the nutrition space – all of us influenced to some degree by our own experiences – the low carbohydrate and fasting space seems to bring with it its own special degree of hysteria. The prevailing message is that both low carbohydrate diets and fasting is too stressful on the endocrine system of females (which regulates hormones) and causes a reduction in metabolism and reproductive potential. Thus, it is to be avoided at all costs. This point of view may be drawn from clinical experience of the practitioner and be dependent on the type of client they see. If their target audience are women who have struggled with maintaining a healthy weight and have problems with eating enough, then the opinion of the practitioner could well be influenced by this (and is entirely sensible!) Likewise, I see many women who’s hormones benefit from periods of intermittent fasting while utilising a LCHF protocol. What we see in clinic will dictate our points of view, regardless of how objective we try to be.

I have in the past written about the negative impact of fasting and calorie restriction on the expression of genes that regulate kisspeptin in the body, a hormone involved in our reproductive cycle. However I will point out that the effects seen in studies conducted in rodents may be more dramatic than if they were carried out as clinical trials in humans. Rodents have a much faster metabolism, thus a 24h fast for a mouse is equivalent to a 3 day fast in humans. Likewise, chronic caloric restriction over a week, where the mice lose close to a quarter of their body weight (and which is thought to be responsible for the downregulation of the kisspeptin receptors that result in negative effects) may be equivalent to 12 or more weeks. Rodent models in science are great for illustrating potential mechanisms, but can never be viewed as hard data as it pertains to humans.

Alongside any scientific data that exists, I think it’s important to step back and consider perspective here. What we should all be aware of is that there is no one right dietary approach for everyone, and often there is no one dietary approach to suit someone for the rest of their lives. As things change, so do our nutritional requirements. Low carbohydrate diet and intermittent fasting is not exempt from this – therefore to say that it is not suitable for any woman is, quite frankly, erroneous and misrepresents what we see in the literature and what we see clinically. While certainly a vast majority of the studies investigating lower carbohydrate diets have been conducted in males, there are studies showing a positive impact for overweight women with infertility. Further, it is accepted best practice to include periods of low glycogen availability in the training schedules of athletes. Even in the researchers who err on the side of pro-carbohydrate diets recommend cycling carbohydrate intake to be sometimes low, and sometimes high, to upregulate fat oxidation pathways that allow the athlete to become more efficient at burning fat. To state that no female athlete should start an exercise session in a fasted state goes against current best practice for endurance performance.

Possibly the negative impacts of fasting and low carbohdyrate diets are not about the fasting period or the carbohydrate content – it’s much more likely to represent chronic underfuelling – i.e. a lack of calories over an extended period of time, with no thought given to cycling of both energy intake and/or macronutrients. It’s just low, full stop. That’s why it is important to work with an experienced sports nutrition practitioner (like me, Kaytee Boyd, Caryn Zinn as some top picks) to ensure these training tactics are used to the advantage of the athlete in a training cycle, not to the detriment of them.

Don’t misread this as a recommendation to do all sessions in a fasted state, to undergo an intermittent fasting protocol that involves skipping breakfast every day of the week, or that everyone should adhere to a very low carbohydrate approach. If you’ve read any of my information (or followed anything I’ve suggested) then you’ll know this isn’t the case. The point of this blog is to remember that there is no one right dietary approach for everyone, and that if you’re successfully adhering to a lower carbohydrate diet with periods of intermittent fasting and feel it’s working well for you (ie no sleep, hormone, training or recovery problems), don’t be concerned with the rhetoric that exists regarding the harmful nature of this. You are your own best investigator when it comes to your nutrition, and your experience is the most important data when it comes to you.

Intermittent fasting

Post on IF, cue picture of empty plate with clock. #standard (PC

LCHF…why isn’t it working for me? (Part 1)

It’s about this time of year that I start seeing people come through my doors needing some minor (or major) tweaks to their LCHF eating approach. There are usually one of two scenarios.

Scenario #1: When they embarked on LCHF they saw ALL of the benefits they heard about, effortlessly shedding body fat, boundless energy (in training and afterwards), improvement in skin tone, hair condition, sleep and digestive problems. But lately the opposite is true. Despite seemingly nailing this LCHF lifestyle, they’ve noticed they are lacking energy, gaining weight (especially around the middle), latest blood tests have seen their cholesterol levels have shot up (and perhaps triglycerides), they are unable to sleep… … yet if anything, they’ve instigated (and nailed) the hacks they’ve read to optimise their LCHF eating approach. What gives??

Scenario #2: They’ve given it a good go on their own for the last 5 weeks, following it to the letter and despite this, it’s ‘not working for them.’ Worse, their husband/workmate/training partner has taken to it with ease.

Frustrating, much?

While we are all individual as to what is going to work for us, the LCHF approach is a really good one for most people, most of the time. Despite that, there are small things that can derail your best efforts to improve your diet, so I want to cover off the basic (and more nuanced) reasons people don’t fare well on a LCHF approach, and some tips on how to overcome them. I’ve ended up splitting this post into two parts as it was so long!

  1. Too low carb. The internet is a wonderful and terrible thing – information is everywhere, everyone is an expert and the version of paleo/LCHF/JERF that you’ve adopted based on what others are doing may well be too low carb for you. LCHF is a spectrum, and what is low carb for one person may well be higher carb for someone else – generally speaking, anything up to 200g of carbohydrate/day could be low carb. It all depends on context. I see a lot of people who are trying to stay strictly below 25g of carbohydrate a day – too strict (and unnecessary) for most people. Even Prof Tim Noakes, staunch advocate of a LCHF approach to eating (“banting”) has loosened up on this. The people who really benefit from a diet this low would be those embarking on it for therapeutic reasons: diabetes (both types), epilepsy, cognitive health (Alzheimer’s, for example). That’s not to say that others out there can’t make this level of carbohydrate work for them. But if you’ve noticed fat gain (especially around the middle), irritability, hormone imbalances (such as a missed menstrual period), lack of energy (past the initial phases of the LCHF approach), irregularity of bowel motions, sleeplessness – to name a few symptoms, then you may have gone too low. What to do?
    1. Track your diet for 4-5 days to get an average of the grams of carbohydrate you eat per day. If it’s on the very low end of the scale (less than 50g*, for example), then try adding back in some good quality starch to see if any of your symptoms improve. Don’t be pedantic about vegetables. Really. That includes carrots and tomatoes. To be honest, you don’t have to track your carbs if you’re not a numbers person – but it can be a good way to assess if this really is the problem. Use My Fitness Pal, Cron-o-meter, My Net Diary or Easy Diet Diary as nutritional tracking tools. (If you’re embarking on a lower carb diet, this is a good first step regardless, so you don’t make the jump from 400g a day to 60g a day).
    2. If your carbohydrate intake is in the realm of 80-100g carbohydrate, you may not be too low, it might be more of a timing problem – ensuring you have carbohydrate in the meal after a high intensity (i.e. CrossFit or F45) or long duration exercise session can help improve recovery and alleviate a lot of fatigue/irritability. If you’re struggling with insomnia, then adding in some kumara or potato into your evening meal increases production of precursors to melatonin.
    3. Is it more protein you need? Protein can help keep you fuller for longer, stabilise blood sugars (therefore has implications for focus/energy/concentration), promote recovery and help with sleep. Many people fear protein because of the potential for it to be converted to glucose in the body (via gluconeogenesis). For someone following a LCHF diet this isn’t an issue. Try upping your protein portions by 1/3 – ½ at each meal.
    4. If it’s in the initial phases, then up your intake of sodium – to levels more than you think you need. When we drop the carbohydrate content of the diet, we drop a lot of water stores too (hence a rapid loss on the scales) – this is because for every gram of carbohydrates stored, we store an additional 3g of water. Add salt to your meals, a pinch in your water bottle, make a miso drink or drink bone broth.
  2. Not low carb enough. I see this a lot. People equate carbohydrate to bread, pasta, rice and cereal and don’t think about other foods that are predominantly carbohydrate –fruit, dried fruit, ‘green smoothies’ with a fruit base, bliss balls, natural fruit and nut bars… In addition, many products are promoted as ‘sugar free’ when they contain dried fruit, maple sugar, rice malt syrup or some other type of natural sweetener. This may seem elementary to you, but I know many people are confused by this point. Regardless of what you hear, sugar IS just sugar – that one sugar is lower in fructose doesn’t mean it’s not going to influence your blood sugar levels, it’s likely to affect them more. This has to be my biggest bugbear of the ‘real food’ movement; not that these products contain sugar – but that they are marketed as not. This is no better than being told that Nutrigrain is healthy. We all know that’s not true.
    1. Again, track your numbers (as per above) via a tracking tool. A lower carbohydrate approach is not a fixed number, it’s a spectrum. But if you’re still consuming over 200g a day and not engaging in regular physical activity, then something might need to be tweaked (especially if you’re not seeing the results you’re after).
    2. Get rid of the bliss balls, the dried fruit, the paleo muffin or the smoothie from your favourite juice bar that you thought tasted suspiciously sweet for something ‘green’.
    3. Read the ingredient lists on the packages you buy. Sugar has over 56 different names. You probably don’t need to know them all, but it would be good to have an idea, right?
  3. Too many processed foods or snacks. Even if you’ve found a sweet spot with your macronutrient intake, having too many processed ‘low carb’ snacks can continue to drive your appetite hormones in a way that favours eating more than you need. Leptin is a hormone produced by fat cells that tells the body when we’ve had enough to eat, and is involved in the regulation of calories we burn and body fat that we store. A consequence of being over-fat is high circulating leptin levels in the bloodstream, and the brain stops reading signals sent by leptin that we’ve consumed enough food. Instead, it incorrectly believes that we are starving, thus we feel hungrier. Excess body fat increases Inflammation in the body, and is one of the drivers of leptin resistance, and processed food can drive inflammatory pathways in the body – even low carb processed food. And if you’re not over-fat? Well, vegetable oils and certain additives and preservatives found in these foods can drive inflammatory pathways in the body. In addition, an overabundance of processed flours may cause disruptions to our gut microbiome as they are easily digested, perhaps not even making it to the gut bacteria in our lower digestive tract. This can mean we are starving our good bacteria and instead feeding bacteria that release endotoxins, causing increasing inflammation. This can have a secondary effect of increasing your cholesterol level (see this post here). These foods are created in such a way to send signals to your brain’s pleasure centre and drive your appetite for more food that you just don’t need. One of the benefits of a real food approach (which naturally lowers your carbohydrate intake) is that inflammation reduces, insulin drops, gut bacteria can rebalance and the signalling pathways in the brain that regulate your appetite hormones can begin to normalise.
    1. Get rid of most foods or snacks that come in a package with ingredients you don’t recognise.
    2. Eat real food. Base your snacks around hardboiled eggs, cheese (for the dairy tolerant), vegetables, leftover meat, macadamia nuts, egg muffins.
    3. Drop the nut flours. Just because they’re low carb does not mean it’s a free for all with these processed flours.
    4. Increase foods that help balance out your fatty acid profile: more fatty fish (such as salmon, mackerel, sardines) and (grass fed) meat for omega 3 fats. Consider taking a fish oil or algae omega for those who don’t eat fish – and be picky about the supplement!
    5. Take care of your gut: consider a probiotic for 30-60 days (such as Lifestream Advanced, Inner Health Plus, Syntol or Prescript Assist) to help populate the gut with the good guys, but also keep them fed with fermented foods such as sauerkraut, raw apple cider vinegar, water kefir and an abundance of vegetable fibres.

I’ve got more – quite a bit more actually! – but will post that in Part 2 so as not to risk losing your attention ;-). These are three of the basics that people can get wrong (particularly in the initial phases), and the next post will cover some of the more nuanced reasons, and what you can do to correct them. If you’re not sure whether your LCHF diet is working for you, why not jump on and book a consultation with me? An expert eye can help take the thinking out of it for you and save a lot of stress long term.

*50g still pretty low actually! Again, it’s all context 😉


Are you in the zone? (PC:

Low carbohydrate diets for health and performance

AUT University’s Human Potential Centre has been commissioned by New Zealand’s Register of Exercise Professionals (REPs) to write research reviews around current exercise and health-related topics that are relevant to the fitness industry. I recently wrote this review of the efficacy of low carbohydrate diets for health and performance. It is definitely longer than my usual posts, so grab a sparkling water and settle in ;). It is appropriate for personal trainers to give guidelines that optimise diet to aid the client’s body composition, health, and performance goals, and then refer clients to a nutritionist or dietitian for a more individualised plan. So, an understanding of the current evidence base on the efficacy of low carbohydrate diets for fat loss and metabolic health outcomes is important hence this review provides a brief summary of current research and some practical tips. In research, a low carbohydrate diet is defined as one that contributes less than 26% of dietary energy (kilojoules) from carbohydrate foods. There is a wide variation in the absolute grams of carbohydrate per day between individuals that would fall into this category. A person who eats 2000 Calories per day would consume less than approximately 120g of carbohydrate, whereas for someone with an intake closer to 2800 Calories per day, less than 170g of carbohydrate would be considered the threshold for ‘low carbohydrate’. As a general rule though, when using absolute amounts, less than 150g of carbohydrate per day is generally considered a low carbohydrate diet – this is compared to the mean intakes of approximately 207g (females) and 278g (males) per day currently consumed in New Zealand. Clearly, low carbohydrate diets are nothing new, with the Letter of Corpulence published in 1863 that instructed readers on the dietary approach that successfully shed weight. The restriction of bread, butter, milk, sugar, beer and potatoes were hallmark features of this plan and provided the foundation for subsequent carbohydrate restricted approaches. In the 1970s the low carbohydrate diet approach was popularised by Dr Robert Atkins and the Atkins Diet Revolution. While at the time this was criticised due to the lack of research around its long term safety (and it was directly opposed to the dietary guidelines at the time), it was the start of the modern era of low carbohydrate diets that included the Scarsdale Diet, Protein Power, South Beach along with updated versions of the Atkins Diet, the latest (A New Atkins for a New You) being released in 2012. A lack of understanding of these diets has led many health professionals to dismiss them as quackery due to a perceived lack of fibre, vitamins and minerals, despite the relative success that some people experience when following a well formulated low carbohydrate diet. The percentage calories coming from fat in a low carbohydrate, high fat (LCHF) diet  is generally around 50-60% depending on individual variation. This naturally increases the amount of fat coming from both animal and plant sources. A major argument used by opponents to the LCHF dietary approach is that it promotes unnaturally high levels of saturated fat in the diet and, as saturated fat increases cholesterol in the body, this will clog arteries and lead to cardiovascular disease. There are a number of issues that need to be addressed here. Firstly, dietary fats don’t exist in nature in isolation, therefore any food that has a high percentage of calories coming from fat will supply the diet with a range of fatty acids and not one type of fat exclusively. For example, an avocado is predominantly monounsaturated fat but contains not insignificant amounts of both polyunsaturated fat and saturated fat. A well formulated LCHF diet will certainly increase levels of saturated fat in the diet, but will also increase levels of all types of fat. A major premise of the LCHF plan is not to eat unnaturally large amounts of fat from any one source. Instead it is to include more of the fat naturally occurring in minimally processed foods (such as some dairy products, plants and animal protein). It is certainly true that an increase in saturated fat leads to an increase in total cholesterol for some people depending on dietary context; however the majority of people see an improvement in their overall lipid profile with the appropriate reduction in carbohydrate as mentioned above. The role of saturated fat in the development of cardiovascular disease is widely disputed in the scientific literature, and while an increase in saturated fat levels in the blood can lead to an increase in atherosclerosis, these levels are increased with a higher intake of refined carbohydrate and not a diet that is high in saturated fats. Further, while the original hypothesis that saturated fat increased cholesterol levels which increases heart disease has been what public health nutrition guidelines have been built around, this has simply not borne out in any randomised controlled trials designed to test this hypothesis. In fact, when comparing the disease outcomes associated with different nutrients, the risk of cardiovascular disease mortality in the US associated with the highest sugar intakes in the USA is 2.75, and in high GI refined carbohydrates it is 1.98, meaning that women with a high consumption of these foods have almost double the risk of dying from cardiovascular disease. The association between the highest saturated fat intakes and heart disease incidence was 1.00, or no association at all. Further, dairy fat – the most saturated of all fats – confers health benefits over and above low fat dairy products due to the type of fatty acids present. Research shows a protective effect with regards to diabetes, cancer and cardiovascular disease, and contribution to obesity. The premise of a low carbohydrate diet for weight loss is built not on the ‘energy in, energy out’ model of weight loss, but the metabolic fate of carbohydrates in the body. While gram for gram, carbohydrate has less than half the number of calories as fat, it triggers hormonal effects which can lead to fat storage. When carbohydrates are ingested, they are digested and broken down into glucose and delivered into the bloodstream, resulting in the release of insulin from the pancreas. Insulin is responsible for disposal of glucose into the cells thus returning the blood stream back to its homeostatic level of glucose (of between 4 mmol/L to 8 mmol/L). Insulin also stimulates the production of glycogen in the liver, and when the liver is saturated with glycogen, the glucose is synthesised into fatty acids to travel in lipoproteins into the bloodstream. The glucose that is transported into the fat cells is synthesised into glycerol and used to create triglycerides. For these reasons, insulin is considered to be a major player in fat storage, and carbohydrate is the macronutrient which has a profound effect on insulin secretion. Protein on the other hand, has a minimal effect on insulin secretion (with the exception of whey protein) and fat does not stimulate insulin release. (For more information, go here). In terms of food, our ability to burn fat if we consume a can of soft drink is compromised compared to consuming two eggs (predominantly fat and protein). This is not to suggest that calories don’t matter, as a calorie deficit still needs to occur for fat loss to be achieved. However, our ability to burn calories stored as fat is far greater when carbohydrate intake is low (as addressed below). The research clearly shows that a greater reduction in weight is achieved when following a LCHF diet compared to conventional dietary advice promoting a low fat, calorie-restricted approach. Researchers have studied LCHF diets in both calorie-restricted and ad-libitum conditions (where participants could eat as much food as they like), and weight loss was greater in the LCHF group. When it came to dietary adherence, as measured by trial completion, low carbohydrate diets achieved better adherence than low fat (i.e., 79.5% vs. 77.7%, respectively). While the difference is marginal, it still indicates from these studies that LCHF diets are at the very least not harder to stick to than other diets. A possible reason for this might be that these diets appear to reduce hunger and participants are permitted to eat until satiated. While people argue that diets high in both fat OR sugar will result in increased energy intake and weight gain, the results of the above studies illustrate the opposite. A low carbohydrate diet may normalise energy intake due to the higher satiety of fat, and this isn’t typically seen in a higher carbohydrate, lower fat approach. In relation to health outcomes, the LCHF diets outperform standard practice guidelines when it comes to lipids, HDL cholesterol and triglycerides, and have similar beneficial outcomes with glycaemic control and blood pressure. There appear to be no serious adverse effects arising from either of the dietary protocols, thereby assuring safety from both. Importantly, in the studies where abdominal fat was measured (which is an independent risk factor for cardiovascular disease), LCHF groups have a clear advantage over low fat diets. A LCHF diet has its benefits for athletes, and utilising fat as a fuel source is advantageous from an endurance sport perspective where performance can be limited by the amount of carbohydrate able to be ingested throughout events greater than 2+ hours. The goal of becoming efficient at burning fat as a fuel source is to enable the athlete to become metabolically flexible (i.e. to be able to burn either fat or carbohydrate) during both training and racing as the intensity of the effort requires it. An athlete who has a high carbohydrate diet is less able to tap into fat stores if their body hasn’t had a chance to adapt to a lower carbohydrate diet, and upregulating the fatty acid pathways in the body helps delay the use of stored glycogen which is beneficial for endurance events. Further, the ability to utilise fat as a fuel source allows for improvements in body composition as less exogenous fuel sources need to be ingested. This also helps reduce the incidence of gastrointestinal issues experienced by many endurance athletes in both training and racing who cannot take in enough carbohydrate to fuel the demands. While it is argued that a low carbohydrate approach to diet is detrimental to an athlete’s performance, when timing carbohydrate intake to meet recovery needs, and when given adequate time for the energy system to change from burning predominantly carbohydrate to burning predominantly fat, most athletes benefit from a LCHF diet. The length of time to adapt is individual, however, and anecdotal reports suggest it can take anywhere from 4-12 weeks in the first instance. Therefore changes to a diet should take place during off season or when an athlete is building base endurance for their event, and not in a period of high intensity training. While the application of an LCHF diet is obvious for an endurance athlete, a lower carbohydrate, higher fat diet may be beneficial for other athletes participating in shorter events of higher intensity or team sport athletes. The timing of carbohydrate intake to fuel glycolytic activity and maximise recovery needs to be addressed, and working with a sports nutritionist or dietitian is required for more specialised advice. One of the main criticisms of a low carbohydrate approach is that carbohydrate is an essential nutrient and cutting this out leads to a reduction in optimal functioning. A nutrient is defined as essential when we can’t produce it in our body and therefore it must be supplied by our diet. As we have a limited storage capacity for carbohydrate (approximately 400-500g depending on muscle mass), this has led to the misconception that we require daily replenishment. Unlike fat and protein, however, our body is very adept at producing glucose through a process known as gluconeogenesis; the production of glucose from both fats and amino acids. We produce roughly 120-140g of glucose per day independent of food intake. A second criticism of a LCHF diet is that the exclusion of food groups (specifically whole grain cereals) leads to a deficit in nutrients. However, a well formulated low carbohydrate diet can be far more efficacious at supplying all nutrients when compared to conventional weight loss dietary advice which is based on providing a low fat diet that is rich in whole grains. In actual fact, very little food sources contain the whole grains that confer actual health benefits and in New Zealand true wholegrains such as pearl barley, brown rice, and pumpernickel bread are not common items of our dietary intake. Most wholegrain breads are made with white flour and other refined additives (they are in fact highly processed foods). The grinding of wholegrains to make flour produces a high-GI carbohydrate. The consumers most convenient guide to what is wholegrain and what is not comes from packaging claims which are more or less misleading. Furthermore, attempts to comply with this recommendation in institutional kitchens often results in the addition of bran to refined grains. A recent meta-analysis has concluded that the health benefits of a diet high in wholegrains could be overstated, and the suggested benefits observed in epidemiological studies are not supported by the clinical trials. In addition, there is increasing prevalence of maladaptive immune responses to proteins of various grains and legumes in a significant proportion of the population. The rate of coeliac disease, while acknowledged as a small population prevalence, is highest in the cultures that eat the largest proportion of diet as wheat. The increasing recognition of sub-optimal health related to non-coeliac gluten sensitivity – including allergies, headaches, gastro-intestinal problems and fatigue – suggest that reducing wheat-based carbohydrate in the diet for many could be beneficial. Phytic acid, which is found in high levels in unrefined grains, binds to minerals, rendering them insoluble, and is linked to deficiencies of iron, zinc, magnesium and calcium. The third major criticism of a LCHF diet is that it leads to ketosis which is a dangerous metabolic state to be in. We are able to burn both glucose and ketones as a fuel source, however given the modern diet, most people preferentially burn glucose. Nutritional ketosis is a state whereby the body burns ketones as opposed to glucose as a fuel source. Ketones are produced from the breakdown of fatty acids and amino acids, of which there are three types: acetone, acetate and betahydroxybutyrate (BOHB). This survival mechanism likely provided humans with a metabolic advantage in prehistoric times when food was scarce and we went for a period of time without fuel. The limited storage capacity for carbohydrate requires an alternative fuel source for the brain (first and foremost) and the ketone bodies produced through ketosis provides these. Nutritional ketosis is when ketone (BOHB) production measured through the blood is around above 0.5mmol/L, with the ideal spot (to confer mental acuity benefits) said to be between 1-3 mmol/L. This state of nutritional ketosis is confused with diabetic ketoacidosis, a serious health condition due to uncontrolled ketone build up in the blood. This comes from the inability to take glucose into the cells in people who aren’t able to produce insulin (typically people with type 1 diabetes). The body recognises this as a fasting state and effectively starts to produce ketones for an alternative fuel source, however there is no ability to clear either ketones or glucose without the provision of insulin and instead the rapid rise in ketones (to levels above 10 mmol/L) can lead to serious metabolic conditions. This is as a result of a low pH level of the blood that can result in nausea, vomiting and unconsciousness. This state is, however, impossible for anyone who can produce insulin as the body has a feedback loop which enables the clearance of glucose and ketones from the bloodstream. Importantly, the level of carbohydrate in the diet required to achieve ketosis is less than 50g per day and, for many, closer to 30g per day. Protein levels also have to be closely monitored due to gluconeogenesis. So, while a low carbohydrate diet can lead to ketosis, this isn’t an inevitable part of embarking on a low carbohydrate diet, and nor is it a requirement for being able to use fat as a primary fuel source. There are many pathways in the body that allow us to use fat as an energy substrate. This includes upregulating lipolysis (the breakdown of fat stores into fatty acids and triglycerides to be used by the muscle as energy); the upregulation of beta oxidation which increases the conversation of fatty acids to acetyl coA (the precursor for the Krebs cycles to produce ATP) and the increase in gluconeogenesis (the conversion of protein and fat to glucose) are all pathways that can aid in fat burning that don’t require a ketogenic diet and instead can be enhanced through following a well formulated LCHF diet. Finally, people mistakenly assume that a low carbohydrate diet must be high in protein and that this is both expensive and unsafe. As mentioned above, a well formulated LCHF diet contains a moderate amount of protein, with the remaining calories coming from fat. In the literature the percentage energy coming from protein is typically in line with standard recommendations for protein intake (between 15-25%). It is also worth mentioning that a higher protein intake is not associated with adverse health outcomes in people who are healthy; those with impairments to their kidneys do need to monitor protein consumption as the kidneys are the organ responsible for processing protein load in the body. For most people this is not a concern. In summary, while there certainly isn’t one diet to suit every individual, a well formulated LCHF dietary approach is beneficial for metabolic, health and sports related outcomes. When designed to optimise nutrient quality, the similarities between this and a ‘paleo’, ‘whole food’ or ‘clean eating’ approach far outweigh the differences. Practical tips:

  • A low carbohydrate, high fat diet (LCHF) is one which the calories from carbohydrate are approximately 25% or less in the dietary intake, and typically below 150g per day in absolute amounts.
  • The premise of a well formulated LCHF diet is one which is based around food quality and consuming food as close to its natural form as possible.
  • Build meals around an abundance of non-starchy vegetables of all colours.
  • The carbohydrate foods consumed on a well-formulated LCHF diet come a small amount of starchy vegetables and legumes, low sugar fruit and full fat dairy products.
  • Incorporate moderate amounts of animal protein, fish and eggs for quality protein sources in a meal.
  • Fats such as butter, coconut oil, lard and olive oil are best to cook with, and other nut oils can be used as dressing for salads. Include avocado, raw nuts and seeds as high fat options in meals and snacks.
  • Processed or highly refined foods, oils and margarines or spreads are best avoided.
  • Incorporating fat and protein in every meal or snack will help minimise blood sugar swings and improve glycaemic control across the day.