For those new to ketogenic diets, they get 60 to 75 per cent of their energy from fat, 15 to 30 per cent from protein and less than 10 per cent from carbohydrate.
The theory is, without adequate carbohydrate and limited protein, the body must switch its primary fuel source to fat.
While it sounds great, it means giving up whole grains, starchy vegetables, fruits, legumes and most dairy products.
While dietitians get uncomfortable excluding so many foods, they have been involved in teaching keto diets for years in the treatment of epilepsy and certain other metabolic conditions.
While keto diets have shown increased weight loss in the short term (up to six months), the long-term evidence (one to five years) shows no significant difference from any other weight loss diet.
What that means is that people have not been successful maintaining their weight loss for more than a year.
We also know that obesity is not only about food.
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It is a complex disorder with genetic, environmental and personal causes; not everybody responds the same way to dieting.
You may follow a diet perfectly and still not reach your ideal weight.
So what is the potential for harm with the keto diet?
Restricting so many foods risks not getting all the vitamins, minerals, dietary fibre and antioxidants needed to keep your body strong.
As with any restriction diet, you may see a reduction of metabolic rate, weight cycling and loss of joy around eating.
To be successful on the ketogenic diet requires a level of dedication as ‘keto’ meals are not readily available in our culture.
This can cause isolation and obsessive thoughts around food and eating.
The truth about dieting is that there is a fine line between hope and realism.
It is important is to choose a dietary pattern that you enjoy enough to stick to for the rest of your life.
That being said, the ketogenic diet does work for some people to lose weight, at least for the short term.
If you are planning on doing the ketogenic diet for an extended period, seeing a dietitian would be a good idea to make sure you are not putting yourself at risk for deficiency.