Low carbohydrate diets have increased in popularity in recent years with the promise of fast weight loss and increased mental stamina. While there is evidence to support these claims, a restrictive diet can be problematic if done incorrectly. If you are interested in trying a low carbohydrate diet but are unsure if it’s right for you, read below for further information.
What is a low carbohydrate diet?
There are three main diets that are considered low carbohydrate - the paleo diet, the ketogenic diet and the Atkins diet. Each has slightly different dietary restrictions, guidelines and purpose.
The ketogenic diet
The main goal is to switch from using glucose (carbohydrate) as a primary fuel source in the body to ketones, a by product of fatty acid (fat) metabolism. The diet emphasis a high intake of healthy fats, restricts dietary protein to 20-25% of total calorie intake and complex carbohydrates (i.e. leafy greens, berries, citrus and legumes) to less than 10% of total calorie intake.
The paleo diet
A way of eating that attempts to copy what our Paleolithic (hunter gatherer) ancestors would have eaten. The diet restricts food categories instead of specific macronutrients… no calorie counting in this diet! Foods not allowed on the paleo diet include all grains, dairy, refined sugars, legumes, potatoes and corn. These restrictions result in a naturally low carbohydrate and high protein intake.
The Atkins diet
Introduced in the 70s, the Atkins diet has largely been marketed for weight loss. It closely resembles the ketogenic diet in terms of total carbohydrate restriction and differs in that it does not place any restrictions on total protein intake. The diet is typically done in phases, the first being the most restrictive (20-25g of net carbohydrate per day). Carbohydrates are gradually added back in throughout the phases to determine the threshold at which weight loss plateaus.
What’s the appeal of low carbohydrate eating?
There a number of reasons people may choose to follow a low carbohydrate diet, the predominant reason being the desire to loose weight. Numerous studies and a plethora of online anecdotal evidence maintain that these diets are successful for weight loss in most individuals. The biggest question we now face is if these diets are sustainable long term for the maintenance of healthy weight.
The use of ketones as the brain’s primary fuel appeals to many for it’s purported benefits on cognition – improved concentration, clarity and memory. Athletes may also follow these diets to achieve their ideal body composition and to improve physical performance, although the evidence in this area is conflicting.
These diets inherently restrict inflammatory foods such as sugar, alcohol and refined carbohydrates. Reducing diet driven inflammation in the body can reverse disorders such as obesity, diabetes, cardiovascular diseases and polycystic ovarian syndrome (PCOS). Reducing systemic inflammation can also benefit the body’s ability to function optimally and prevent future disease in healthy individuals.
Where things can go wrong
Trying to self-guide a new way of eating can be tricky to adjust to and result in giving up and feeling disappointed. For some, a low carbohydrate diet is easy to follow, but if done improperly, results in inadequate intake of nutrients. These diets can even be dangerous in some people e.g. diabetics who are dependent on insulin.
During the switch to a new way of eating getting stuck for ideas on what to eat is common, especially if all your previously staple foods are now removed or restricted. A naturopath or nutritionist familiar with low carbohydrate diets can brainstorm ideas with you that are tailored to your budget, preferences and time available.
Difficulty adjusting can also refer to the physiological process of switching to a new way of metabolising macronutrients i.e. the ratio of fats, carbohydrates and proteins. The ‘keto flu’ is a well know phenomenon that occurs in the first few days of the ketogenic diet. It mimics symptoms of a hangover (tired, headachy, sore, nauseas or constipated) and can last for days in some people.
A few tricks to avoid or reduce these side effects includes drinking more water, having more sea or pink salt (for trace minerals), eating more vegetables, taking apple cider vinegar and eating more healthy fats such as fish, olives, avocado or coconut products.
Inadequate micronutrient intake
You’ll likely feel excited when you find something that you love to eat and it satisfies all the rules of the diet! So you’ll start to eat this food everyday and it will become a ‘core’ part of your eating habits. But one of the most important rules with any diet is to have variety in the foods you eat so you are sure to get a wide array of vitamins and minerals.
To avoid the risk of malnourishment, familiarise yourself with all the allowable foods of the diet and set yourself a goal to include as many of them as possible. This process sure can take some time, so be prepared to make extra time in your day for researching recipes, cooking and experimenting with new ingredients.
Inadequate fibre intake
With a restriction in carbohydrates also often comes a restriction in soluble and insoluble fibres. These are the nutrients that are needed to feed the ecosystem of your gut! If you restrict fibre, your beneficial bugs are not getting fed, which can result in changes to your digestive function (e.g. constipation, nausea and abdominal pain) as well as negatively impact your overall health in the long term. Opinions on the appropriateness of low carbohydrate diets long term are conflicting based on current limited knowledge of how these diets affect the microbiome in the long term.
To ensure you are supporting your gut’s ecosystem during a low carbohydrate diet, eat a wide variety of vegetables within the parameters of the carbohydrate restriction and consider supplementing with fibrous powders and foods such as LSA mix, psyllium husk, guar gum, slippery elm and konjac noodles.
The take home message
Low carbohydrate diets do offer benefit, however they are not suitable for everyone and do pose some long-term risks. If you are unsure if a low carbohydrate diet is right for you, get in contact with a health practitioner trained in nutrition and gut health to ensure you do it right!
By Lucy Mason, Naturopath