How and why the Atkins diet works

The Atkins diet works by switching your body to burning fat (including your own body fat) instead of sugar (carbohydrates) as its primary fuel source. That’s it! It basically turns your body into a fat burning machine! Sound good so far?

Fats have long been blamed for making us fat but the real issue is an excess of carbohydrates particularly the carbohydrates found in refined processed foods. The Atkins diet is about replacing high carb foods including refined processed foods (like pasta, bread, baked goods, fizzy drinks and junk food in general) with lots of vegetables, salads, meat, fish and poultry as well as healthy fats. So real Irish butter and cream is fine as is proper full-fat mayonnaise! See the Food List page for a full list of the healthy foods you can eat on the Atkins diet.

Replacing refined processed foods with healthy whole foods

When you digest foods high in carbohydrates, they convert quickly to glucose (sugar), which your bloodstream transports throughout your body. A rise in blood sugar level triggers the release of the hormone insulin. The function of insulin is to bring your blood sugar back down to normal levels. The way it does this is by using some of the glucose as energy and the rest gets stored as fat.

A key point is that when the body has a choice of using fat or carbs as a fuel source it always uses carbs first. The reason for this is that our bodies can only store half a days supply of glucose whereas it can store almost limitless amounts of fat. So its easiest for our bodies to use up the carbs first for energy but then it needs to store all of the extra as fat.

So here is the scenario in a typical day for someone on the ‘Western diet’:

  • We have cereal, toast, orange juice for breakfast – foods all high in carbs.
  • This converts to glucose quickly causing our blood sugar to rise.
  • Insulin levels rise to deal with the rising tide of blood sugar.
  • We don’t need all of that glucose for energy so the extra gets stored as fat – usually around our middle – this is the case with men and women.
  • Mid morning – we have another high carb snack – pastry, scone etc.
  • Lunch – sandwich/wrap/rolls – starts the high sugar spike/roller-coaster again i.e. carbs converted to glucose in our blood, release of insulin, storage of excess glucose as fat..
  • Our sugar levels dip too low – causing that afternoon slump. Can leave us feeling tired, in bad humour and craving more carbs..
  • As a result our body never gets to use our fat stores for energy..

What happens when we eat high carb foods

For more information on how the Atkins diet works, check out the official Atkins site.

For someone on the Atkins diet, the level of carbs in the diet are low so the sugar spike does not happen and insulin is not triggered. The carbs that you do eat are in the form of high-fiber whole foods, which convert to glucose relatively slowly. So your body uses fat for fuel instead. A nice side effect of this is that you lose weight! And because you do not have the sugar spikes and associated crashes, your energy levels hold steady.

Find out about the induction phase here