Is this new fat diet actually good for us?

QUESTION The new dietary buzzword is ketosis. What is it? Is it good or bad?

JUST like your car uses petrol, your body needs fuel – usually glucose. On a ketogenic or keto diet, often low in carbohydrate and higher in fat, the body is starved of glucose.

It means the liver’s back-up glucose levels are depleted, blood sugar and insulin are lowered and the body looks for another fuel source: fat.

Ketosis leads to a build-up of acids called ketones. The molecules are acetoacetate, beta-hydroxybutyrate and their breakdown product, acetone.

These three are converted into acetyl-CoA, which enters the citric acid cycle and is oxidised in cells’ mitochondria to provide energy.

Intermittent fasting, with a ketogenic diet of about 80-90% fat with moderate protein but limited carbohydrate and a lot of exercise, can shift the body into a state of ketosis.

A keto diet can cause sideeffects such as weakness, headache, mental fatigue, irritability or ‘keto flu’ – mild flu-like symptoms. These should stop after a few weeks. If not, stop the diet and see a doctor.

Generally, ketosis should not cause health problems (although diabetics should be aware of ketoacidosis).

It can also aid weight loss, lower blood pressure, increase HDL (good) cholesterol levels and raise mental performance. After all, humans evolved this back-up energy supply to cope with times of enforced fasting. Dr Ian Smith,

Cambridge.

QUESTION Why is KFC known as PFK in Quebec?

FURTHER to earlier answers, years ago in Montreal, we saw an example of how French Canadians can be more French than the French: a café called a hot dog a ‘chien chaud’.

Hugh McCrea, Dunblane, Stirlingshire.