In most cases, the macronutrient profile for a keto diet for beginners consists of about 5–10% carbohydrates, 15–25% protein, and the remaining 65–80% from fat. By restricting glucogenic substrates (i.e. nutrients that increase blood glucose levels, like carbohydrates and glucogenic amino acids from proteins), a deeper level of ketosis can be achieved, which may have a plethora of benefits as discussed below. As an example, one study compared diets with 30, 60, and 100 grams of carbohydrates per day and found that restricting carbohydrates to 30 grams led to a greater increase in circulating ketone levels and body fat loss.
Body Composition: Physical changes in the body are one of the primary reasons people are attracted to and implement low-carbohydrate diets. By definition, being in a state of ketosis means you are able to tap into the body’s fat stores, metabolizing fat for immediate energy and producing ketones for fuel. Furthermore, the ketogenic diet has been shown to reduce circulating insulin levels, which may lead to less storage of fat by the hormone insulin. While both “low-carbohydrate” and ketogenic diets are effective for weight loss, studies have demonstrated that the ketogenic diet is superior.
On the ketogenic diet, carbohydrates are restricted and so cannot provide for all the metabolic needs of the body. Instead, fatty acids are used as the major source of fuel. These are used through fatty-acid oxidation in the cell's mitochondria (the energy-producing parts of the cell). Humans can convert some amino acids into glucose by a process called gluconeogenesis, but cannot do this by using fatty acids. Since amino acids are needed to make proteins, which are essential for growth and repair of body tissues, these cannot be used only to produce glucose. This could pose a problem for the brain, since it is normally fuelled solely by glucose, and most fatty acids do not cross the blood–brain barrier. However, the liver can use long-chain fatty acids to synthesise the three ketone bodies β-hydroxybutyrate, acetoacetate and acetone. These ketone bodies enter the brain and partially substitute for blood glucose as a source of energy.
Cruciferous vegetables, also known as brassicas and “cole crops”, such as broccoli, cauliflower, cabbage and Brussels sprouts, are truly a low-carber’s best friend! They are the perfect replacement for starchy ingredients such as potatoes, rice and pasta. You can turn them into everything from mash to pizza crusts – true keto magic! Did we mention that most of them are super cheap, environmentally friendly and packed with nutrients, too?