When you're trying to lose weight, get into shape or manage a condition like type 2 diabetes, it can be confusing to choose from the 20 different diets that all promise superb health and massive weight loss.
One diet that has gained popularity of late is the ketogenic diet, also known as the 'keto diet', a strict low carb, high fat way of eating.
To find out more about the keto diet, The Huffington Post Australia spoke to two health experts.
What is the ketogenic diet?
"The keto diet is basically a very low-carb diet to encourage the body to use fat as fuel instead of glucose," nutritionist Fiona Tuck told HuffPost Australia. "The lower the carbohydrate intake, the quicker the body enters a fat burning state."
The diet promotes eating fewer than 50 grams of carbohydrates a day to encourage the body into a state of ketosis, where the body is almost completely fuelled by fat (rather than glucose in the form of carbohydrates).
"When we dramatically limit carbohydrate intake, the body needs to look for an alternate fuel source, calling on the body to convert its supply of fat to glucose, a process called ketosis," Tuck said.
"Ketosis produces ketone bodies which are produced from the breakdown of fats in the liver. When the body calls on fat stores to supply energy, we lose weight.
"Some keto diets promote as little as 15-20 grams of carbohydrates a day. Carbohydrates are contained in a variety of foods such as bread, rice, pasta, whole grains, fruits and starchy vegetables."
Why low carb, high fat?
According to nutritionist Anthony Power, by drastically reducing cabrohydrates in the diet, increasing fat and pushing the body into ketosis, the body uses a more stable source of fuel.
"The ketogenic diet is producing an alternative fuel for the body, not fuelling primarily on glucose from carbohydrates. It's fuelling on the breakdown of fat. We don't need outside glucose," Power said.
"A few thousand years ago, the body needed to be able to breakdown our own fat, or fat in animal products, to fuel our brain and body. And it did that by ketones."
Fat also has a much smaller impact on blood sugar levels, Power added, especially compared to carbohydrates and protein.
The pros
While giving up carbs sounds like an impossible feat, there are two significant pros for the ketogenic diet.
"The positives -- it's a quick and reliable way to lose weight quickly," Tuck said. "So it's better suited to someone that needs to lose weight quickly in a short period of time. For example, a morbidly obese person in need of medical intervention."
Because fat does not impact insulin the way carbohydrates too, Power said the ketogenic diet is ideal for people who are diabetic or insulin resistant. Research is proving this to be effective, too.
"The World Health Organisation currently estimates that 400 million people worldwide have diabetes -- nearly half a billion people," Power said. "Why? Because eating carbohydrates (which converts to glucose) then increases our blood sugar, increases our insulin, leads to weight gain and eventually heart disease and diabetes.
"The majority of patients I use the ketogenic diet for are diabetics, those with heart disease and gastrointestinal tract issues (reflux, constipation, bloating), and they've had great results when they reduce their carbohydrates."
The cons
According to Tuck, following a ketogenic diet can be potentially damaging to health, particularly in terms of nutritional deficiencies.
"If followed under medical supervision for a short period of time, it can be very successful. However, long term is not recommended due to potential side effects," Tuck said.
"Side effects of a long term ketogenic diet can include muscle loss, dizziness, loss of mental clarity and focus, kidney damage and acidosis.
"Cutting out food groups for a long period of time may also put the body at risk of nutritional deficiencies. Limiting carbohydrate intake means a higher fat and protein intake, leading to possible over-consumption of saturated fats and proteins."
Due to the strict nature of the diet, following a ketogenic diet can also be isolating and unsustainable.
"Cutting out carbohydrates to the degree that is required for the body to go into ketosis makes the diet very limited and potentially antisocial to follow," Tuck said.
Keto diet guidelines
Before starting any diet, it's important to see a GP, particularly those with health conditions, who are elderly, pregnant, on medication and who have a high intensity job and rely on mental alertness or physical exertion.
"Whatever diet you start, do it for a reason and have an endpoint," Power explained.
And if you don't need to diet, don't.
"If you're getting along fine in terms of the food you're eating, your body is not inflamed, you're not diabetic, you're not overweight, then terrific. But for those 400 million patients in the world today, putting them on a carbohydrate restricted diet works."
The main principles of the keto diet is a reduction of carbs to 50 grams or fewer, and an increase in fats.
"The ideal fat is grass-fed meat and butter, olive oil, avocado, oily fish, nuts and seeds -- not having mountains of highly processed vegetable oils or margarine that have been highly treated," Power said.
A person can check whether they're actually in a state of ketosis through urine testing strips as well as through blood and breath tests.
Power does warn people against starting the ketogenic diet without supervision or properly researching (researching online for 10 minutes doesn't count).
"That's the problem. Patients can feel pretty bad -- achy, irritable, poor sleep, cramping," Power told HuffPost Australia. "But they haven't increased their sodium, potassium or magnesium.
"When you go on a ketogenic diet, your body does change, including levels of electrolytes, potassium, sodium and magnesium. You're changing in a positive way but for many patients, for the first few weeks (especially those who are diabetic or have blood sugar issues) you have to really monitor it."
Even still, the ketogenic diet may not work for you.
"Everyone responds differently. You may lose 30 kilos, your best friend may lose three kilos and feel horrible. It's such an individual thing," Power said.
"It's not 'no carbohydrates' forever. It's just finding what amount is good for you and finding that sweet spot."
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