While the list of popular diets grows exponentially every year, no diet has ever persisted quite like the low carb diet.
Low carb diets are usually described as having <50-65g carbohydrate per day, sometimes as low as 20g. In comparison, the Australian Dietary Guidelines recommend that carbohydrates contribute between 45-65% of total energy intake.
On average, this would be 240 – 350g per day for males, and 170 – 240g per day for females.
Three trending low -carb diets are the Keto, Paleo and CSIRO Low Carb. We’ve summarized the key points below:
What is it: A diet originally developed in the 1920s to treat children with epilepsy. It encourages approximately 70% of your daily energy requirements to come from fats, 20% from protein, and 10% from carbohydrate. Achieving these figures will require a carbohydrate restriction of <20-50g/day.
How does it work? Supposedly, this diet will encourage your body to become more efficient at burning fats – including dietary intake and body fat reserves. There are no set caloric targets or serving size limits for this diet – this is because the satiating effect of high fat/protein meals, coupled by the effect of ketosis on reducing appetite, naturally restricts food intake.
Foods off limits: All grains and grain products, starchy vegetables, legumes, fruit (except berries), cow’s milk.
Foods encouraged: Oils, nuts and seeds, avocado, salmon and fish, coconut, meat, poultry, full fat dairy (except milk), eggs, non-starchy vegetables, berries.Note: Most Keto diet guidelines do not distinguish between ‘healthy’ and ‘unhealthy’ fats. For example, heavy cream and avocado are encouraged equally, and processed meats are accepted.
What is it? the paleo diet allows you to eat only those foods that humans ate when they first roamed the planet millions of years ago.
How does it work? Similarly, to the keto diet, the Paleo diet may encourage reduced caloric intake due to the satiating effect of high protein meals. And, of course, when we cut out processed junk food, weight loss is almost inevitable. There are no set caloric targets or serving size limits for this diet.
Foods off limits: All processed grain products (i.e. bread, pasta, rice, cereals), sugars and syrups, fatty and processed meats, all dairy foods, legumes, and artificial sweeteners. Some versions will also ban starchy vegetables (i.e. sweet potato), higher-sugar fruits and fruit products (i.e. banana, mango, dates, fruit juices) and wholegrains (i.e. oats, quinoa, buckwheat).
Foods encouraged: Lean meat (particularly game meat), poultry, fish, eggs, nuts and seeds, fruits, vegetables, avocado, coconut, oils
CSIRO Low Carb Diet
What is it? Developed by the CSIRO institute, this is an evidence-based diet shown to support weight loss and reduce cholesterol and blood sugar levels. It is specifically targeted at individuals with pre-existing metabolic disorders, including diabetes or pre-diabetes.
How does it work? Unlike the two examples above, the CSIRO Low Carb diet restricts carbohydrate intake significantly, without eliminating altogether. This diet also restricts total caloric and saturated fat intake, and promotes the replacement of carbohydrate with lean proteins and high fibre plant foods.
Foods off limits: Wholegrain carbohydrates, starchy vegetables, legumes and fruits are limited to 1.5 serves/day for the first 7 weeks. This limit is increased to 3.5 serves/day from week 8 onwards. Indulgence foods (i.e. alcohol, chocolate) are allowed in portion-controlled amounts twice a week.
Foods encouraged: Lean meat, poultry, fish, tofu, low fat dairy, eggs, nuts and seeds, avocado, olive oil, non-starchy vegetables.
What are the experts saying about low carb diets?
Some studies have shown that low-carb diets are the most effective for short term weight loss, even more so than the Mediterranean Diet. This may have to do with the high satiety factor of proteins and healthy fats, and the ‘ketosis’ affect of lowering appetite. However, when calories are controlled between study diets, there seems to be minimal or no additional weight loss benefit for low-carb compared with other diets.
Weight loss aside, low-carb diets seem to have a competitive edge when it comes to reducing triglyceride levels, increasing HDL (i.e. “good cholesterol”), and improving glycaemic control for people with type 2 diabetes and insulin resistance.
A recent study published in The Lancet Public Health Journal (August 2018) has demonstrated that diets replacing carbs with proteins and fats from animal sources, including beef, lamb, pork, chicken and cheese, were linked with a greater risk of early death. However, this same study observed that replacing carbohydrates with proteins and fats from plant sources, such as vegetables, legumes and nuts, or oily fish such as salmon may, in fact, increase life expectancy.
When assessing the role of carbohydrates in health and well-being, it is important to differentiate between wholegrain and refined sources. We can all live safely without white bread, soft drinks and rice crackers. But high-fibre carbohydrates such as legumes, starchy vegetables, fruits, multigrain sourdough, quinoa, oats and dairy offer many health benefits, particularly for your gut!
What’s The Nutrition Code verdict?
Don’t get us wrong – we love our ‘good carbs’, and we don’t subscribe to the notion ‘carbs are the devil’. However, whilst many of our peers turn their noses up at diets that eliminate food groups, we like to keep our minds open. Under the proper guidance, we believe that a low carb diet focusing on healthy fats, plant proteins and fibre may be successful for achieving your weight loss and health goals. If you are keen to explore low-carb diets, we can support you in developing a menu plan that is nutritionally balanced and sustainable.
However, no matter which eating pattern you choose, it’s the ability to stick with it that matters. We are all programmed differently – and what works for one doesn’t necessarily work for all. Whilst some people report ‘thriving’ on low-carb diets, many others experience fatigue, headaches, cravings, poor exercise tolerance and constipation. These symptoms are sometimes referred to as ‘keto flu’.
So, if you can’t sustain a low-carb diet long term, don’t worry – most people can’t! If you are committed to this approach, perhaps intermittent carb-fasting (see our July Newsletter ‘the 2 day diet’), an overall reduction in carbohydrate portions, or simply choosing ‘smarter carbs’, will work better for you. These are topics we can discuss together.
Alternatively, why not drop the focus on carbohydrates altogether, and focus instead on a balanced ‘wholefood’ diet that achieves calorie deficit by reducing portion sizes, boredom snacking and emotional eating? Herein lies the key to successful weight loss for most people!