What you need to know about the keto diet

Keto – it’s the diet of the moment, with a band of passionate famous followers. But what is it, and how does it work?  

Actress Halle Berry has eaten a ketogenic-style diet for years, while Megan Fox says keto helped her regain her figure after the birth of her children.  

Kourtney Kardashian also follows a diet plan low in carbohydrates and high in healthy fats – just like the keto diet. 

It’s a weight loss method that is gaining popularity, but what is the ketogenic diet? 

The keto diet in a nutshell

Essentially, keto is an eating plan that is very low on carbohydrates, moderate in protein but extremely high in fat.  

The classic ketogenic diet is based on a 4:1 ratio – so you eat 4g of fat for every combined 1g of protein and carbohydrate.  

But University of Newcastle nutrition and dietetics Professor Clare Collins says this ratio is used only in medical nutrition therapy and is very hard to stick to due to side effects.

Most people are carefully monitored and often graded down to a 3:1 or 2:1 ratio.

ketogenic diet, keto food, high fats, healthy heart food

How the keto diet works

If you think of your body as a car, its preferred fuel would be blood glucose – which you get from eating carbohydrate foods, says Prof Collins. 

You also get that fuel from stored carbohydrates in your muscles called glycogen. 

“When you don’t eat carbohydrates, your body pulls glycogen out of the muscles and when that runs out you start burning fat stores,” she says. 

“This produces ketones and while this isn’t our preferred fuel, our body and brain are clever and can run on ketones – but with side effects.”  

Why the keto diet works

While the ketogenic diet burns fat, the range of foods that can be eaten is limited.  

Prof Collins says between really high-fat foods and prohibited foods, keto diet followers eat less – which leads to weight loss.   

“There’s nothing really magical about it. Your daily carbohydrate intake might be as little as a slice of bread. And the high amount of fat can lead to feeling slightly nauseous, so you don’t eat as much,” says Professor Collins. 

Swedish study found that when we produce ketones, people seemed to tolerate hunger better, although researchers were not sure why. 

keto diet

Which foods are (and aren’t) included in the keto diet?

  • What you can eat: Fish, beef, lamb, chicken, eggs, spinach, kale, broccoli, cauliflower, hard cheese, high fat cream, butter, high-fat salad dressing, nuts and seeds, avocado, berries. 
  • What you can’t eat: Wheat, corn, rice, cereal, cakes, biscuits, pastries, chips, pizza, honey, maple syrup, apples, bananas, oranges, potatoes. 

The things to be aware of on the keto diet

Eating limited vegetables and carbohydrates means low fibre intake, so constipation is a risk.  

The diet is also low in nutrients like vitamin B, folate and iodine – all important for overall health.  

Producing ketones can also lead to bad breath and people may experience nausea and headaches and be at risk of dehydration.  

“Your body mobilises fat out of the liver and that can stir up inflammation and perhaps fatty liver disease or gallbladder disease,” says Prof Collins.  

“If you want to lose weight rapidly in the short term, removing foods and drinks that contain highly processed carbohydrates is recommended. That will lower your total carbohydrate intake. The classical ketogenic diet is not a recommended strategy for weight loss.”   

Trying to lose some body fatRead Healthy Mummy founder Rhian Allen’s top tips to lose baby weight, why one expert believes an interval approach to weight loss is the most effective, and more on dieting. 

Written by Sarah Marinos