The keto diet has been a trendy buzzword for several years, and it’s often mentioned alongside weight-loss diets such as South Beach and Atkins. However, keto works on a different principle, and while weight loss is common, it’s not the only or main goal for some followers: it has also been used to help manage energy levels, tiredness and even medical conditions.
What’s the science behind the keto diet?
Human bodies are, generally, quite effective at extracting, using and storing energy from food. While extra stores of energy (body fat) were an advantage when we routinely faced food shortages (for example, during late winter and spring, while new plants grow), many people now face an over-abundance of calories, which is often, ironically, paired with a shortage of healthy or nutritious foods. This is exacerbating physical and mental health problems for individuals and society as a whole.
Most people eat a diet that is heavy in grains (bread, cereal, rice, cake…), fruit, vegetables, and sugars, all of which are easily turned into glucose, one of the body’s fuels. A keto diet or keto lifestyle aims to shift away from using glucose as a fuel and force the body into ketosis, where it uses ketones as fuel. Ketones are produced by the liver and derived from fat, instead of carbs or sugars.
How does a keto diet cause weight loss?
As well as switching away from using glucose as a fuel, a keto weight-loss diet will involve some calorie restriction. By forcing the body to use ketones as its fuel, this can encourage the use of fat stores and trigger weight loss.
A keto weight-loss diet will typically still involve eating high amounts of fat, and while it might seem counter-intuitive to try to lose fat by eating more fat, by encouraging your body to use fat for fuel, you may be able to shift those fat reserves.
Is a keto diet safe?
As with many things, from eating a pretzel to crossing the road, a keto diet can be unsafe if you do it in a dangerous way, but for most people, most of the time, it is safe. In many cases, shifting to a keto lifestyle involves a dramatic change in diet. This can be a shock, both physically and mentally, as you have to change the way you shop, cook and eat. It can cause longer term problems if you drop too many calories from your diet; if you don’t maintain your intake of essential nutrients, such as vitamins; or if you have other health conditions. If you are pregnant, have liver problems, have a history of eating problems or conditions such as anorexia, have any other health issues or any concerns at all, speak to a medical professional who can help you understand whether the keto diet is a good choice for you.
What does the keto diet involve?
To put your body in ketosis, it is recommended you get around 75% of your daily calories from fat, with 20% from protein and 5% or less from carbohydrates and sugars. As an example, for a 2,000 calorie daily diet, this would be something like 1,500 calories from fat (approximately 167g), 400 from protein (approximately 100g), and 100 calories from carbs (approximately 25g). A single medium banana or a piece of sliced bread is about 100 calories which comes almost entirely from carbs, so that would be your daily allowance. You can still have a full plate – most foods are largely water, which has no calories. As an example, 100g of mushrooms contains just 22 calories.
So what can I actually eat on a keto diet?
A keto diet will focus on fat. Many people will find they easily get the recommended protein alongside the fats, so let’s focus on high-fat, low carb foods. These include:
- dairy products, including cheese, butter, cream, milk and yoghurt (without added fruit or sugar)
- low-carb non-dairy substitutes, such as margarine, almond milk and coconut cream (if unsweetened)
- eggs
- fatty fish, such as salmon, trout, tuna and mackerel
- fatty meats and meat products, such as red meat, steak, ham, bacon, sausage, lard
- poultry, including chicken and turkey
- nuts and seeds
- low-carb vegetables, including green leafy vegetables, broccoli, cauliflower, peppers, tomatoes, squash, cucumber, mushrooms
- high-fat vegetables, such as avocados and olives (these are rare)
- oils such as olive oil, avocado oil, cooking oils
- spices and seasonings, such as salt, pepper, herbs and spices
- a few non-sugar sweeteners, such as stevia, sucralose and xylitol
- no-carb, no-sugar drinks such as green tea, coffee, water
- dark chocolate or cocoa powder (90%+ cocoa solids)
You’ll notice that there are no fruits or juices on this list, no sugar, and no grains (rice, wheat, oats, etc). Also missing are starchy root vegetables (such as potatoes, carrots, sweet potatoes) and other vegetables (such as beans, corn, butternut squash) which contain high levels of carbs. Alcohol is to be avoided, as are most sugar-free sodas and many sweeteners. This excludes a lot of pre-made, packaged and convenience foods, from ketchup and biscuits to a vegan sweet potato curry or your nan’s fruit salad. Even fairly plain packaged foods, such as a salad or yogurt, often have hidden sugars, grains or starches which can wreck a keto diet day. For this reason, many people find it easier to track their food through a general diet app or a keto specific app.
Is the keto diet for me?
For most people, the keto diet involves a radical change in almost every aspect of how they shop, cook and eat, from breakfast through dinner. For some people, this can be what they need to shake unhealthy habits and overconsumption, while for others the overwhelming number of decisions will make it almost impossible to maintain. The keto diet only works if you can force your body into ketosis and maintain that, so it is important to stick to the programme if you want results.
That said, as well as weight loss and potential health benefits, a keto diet can force you to refocus your food intake, and shift to a more thoughtful diet with better quality meats, dairy products with fewer additives, more home-made meals and cut out junk foods and empty snacking entirely. If this appeals, then these changes provide their own benefits for your health, your wallet and the planet. We recommend browsing online meal plans or weekly menus for one which sounds both delicious and doable, then simply trying it for a week.