The sound advice given by the nutritionist in this article can be summed up by the idea of watch your macros and your calories. While we now know weight loss and gain is not as simple as calories in/calories out it is true that calories still do have impact. If you’re consuming too many you will gain weight.
The problem comes when the nutritionist puts for the old idea of your brain requiring carbohydrates as its main fuel source. We now know as well that the brain uses ketones and can easily forgo glucose. So, take what you read with a grain of salt… and maybe a pat of butter… and perhaps even a strip of bacon.
“Fat contains more calories than carbohydrate (which isn’t a bad thing in the slightest!) so it may be worth monitoring your energy intake if the purpose of the diet is for weight loss.”Express.co.uk
Eating a calorie deficit is key for weight loss, and so those eating a new high fat diet may mistakenly eat more calories than they are used to switching to a low-carb diet.