What is ketosis?
Ketosis is a metabolic process in which the body uses stored fat as its primary energy source. It’s a natural fasting metabolic-adapted state which takes place in the absence of sufficient intake of dietary carbohydrates and is what happens whilst we’re on a very low calorie diet (VLCD).
How Does the Body Enter Ketosis?
Ketosis begins when you significantly limit, or completely cease dietary carbohydrate intake. As a result, your body is forced into metabolically switching from using the sugars in our bloodstream, which we would normally get by eating carbohydrates, to burning its fat stores. These stored fats are broken down into their component fatty acids which then undergo conversion in the liver, into ketone bodies. These ketones are created to be used as an alternate source of fuel, especially for the brain, which can only otherwise use sugar. Transition into ketosis occurs quite quickly after reducing our carbohydrate intake, or during fasting, and metabolically switching to fat burning is usually achieved in about three to four days (depending on body size).
Signs and Symptoms of Ketosis
Common indicators include:
- Breath and Urine Changes: Your breath may smell fruity or like nail polish remover, and your urine may have a distinct scent.
- Increased Thirst: Glycogen depletion releases stored water which can make you feel thirstier.
- Reduced Appetite: Ketones are scientifically documented to naturally suppress hunger, which can very often lead to decreased food intake.
Why Is Ketosis Useful?
Ketosis enables your body to efficiently use fat for fuel and is proven to be particularly useful in weight loss and management. Being able to switch into ketosis has given humans some evolutionary advantages too including helping maintain optimum brain function during times when food is scarce. It also spares muscle tissue from being broken down to produce glucose via a process called gluconeogenesis. This is particularly important during weight loss because there are direct benefits from retaining as much lean tissue as possible. There are also many reports of enhanced mental clarity that have been described by individuals in dietary ketosis although individual responses do vary.
What to Expect When Starting Ketosis
During the first few days of reduced carbohydrate intake, when your body is metabolically switching from sugar-burning to fat-burning, you may experience symptoms known as the “keto flu.” These can include feelings of fatigue, headaches, and mild nausea, although they typically subside within a week once the body has adapted to fat-burning.
FAQs About Ketosis
Q: What is ketosis?
A: Ketosis is the metabolic state in which the body has shifted to using fat as its primary energy source, which results in the production of ketones to be used as fuel in place of carbohydrates.
Q: How do I know I’m in ketosis?
A: You may notice breath and urine changes, increased thirst, and a decrease in appetite.
Q: Can ketosis cause diarrhoea?
A: Yes, you can sometimes experience diarrhoea, especially in the initial stages. This may also occur due to changes in dietary fibre intake or an increased consumption of sugar alcohols, which are often found in low-carbohydrate products. The effects are usually temporary, but if they persist, it’s important to consult with a healthcare professional.
Q: Can ketosis cause bad breath?
A: Yes, ketosis can cause very specific changes in breath smell and is often described as being a fruity or metallic smell (like pear drops, or even nail polish remover). This is due to the production of acetone, a type of ketone, which is exhaled through the lungs as your body burns fat for energy. Staying hydrated, maintaining good oral hygiene, and chewing sugar-free gum may help manage this side effect.
Q: Can ketosis make you dizzy?
A: It is possible to experience some dizziness when entering ketosis, particularly in the initial stages. Ensuring adequate fluid intake and replenishing electrolytes through foods or supplements can help alleviate this, and of course, this should subside after a few days.
Q: How many calories break ketosis?
A: Ketosis is primarily influenced by carbohydrate intake rather than overall calories consumed. The intake of too many carbohydrates, 60-70 grams per day (although this varies by individual) can break ketosis, regardless of calorie intake. While calorie control is important for weight management, staying within your personal carbohydrate limit is key to maintaining ketosis.
