Carbohydrate Cycling For Fat Loss

Calorie cycling is a recurring theme in the natural world.

Plants wait for the abundant solar energy of spring and summer to grow. Whales migrate thousands of miles across empty oceans to feast in rich feeding grounds. Ruminants of the Serengeti endure harsh dry seasons then gorge in the banquets of the wet. Tigers, lions and other big predators suffer multiple failed attempts before a successful hunt.

For many thousands of years we would have been subjected to our own cycles of food scarcity and abundance.

Not so any more.

Starting with the first agricultural societies and increasing at an ever faster rate the proliferation of technology has eliminated food scarcity in large (but sadly not all) corners of the world. For all its benefits this age of unrelenting food abundance has coincided with the bulging of our waistlines and a rapid escalation of modern diseases.

By restoring the ups and downs of calorie availability found in nature many fitness enthusiasts have discovered an effective method of burning body fat, curbing weight gain and enhancing body composition. The idea is simple, eat more on days you workout to fuel muscle growth, eat less on days you don’t so your body is forced to burn stored fat reserves. Renowned sports scientist Dr Fred Hatfield calls this approach the Zig Zag Diet.

By applying an additional twist to this calorie cycling strategy many bodybuilders, figure competitors and fitness models have been able to further enhance their fat loss results.

The twist, carb cycling!

In this scenario calories along with carbohydrates are fluctuated on a predetermined cycle. Some days higher in calories and carbs, other days lower in calories and carbs. Typically this would be synced with training and non-training days but other variations do exist.

In simple form this is how it might look;


  • Training Days - Eat higher total calories derived from protein, starchy carbs and healthy fats
  • Non-Training Days - Eat fewer total calories derived from protein,  fibrous carbs (e.g. veggies) and healthy fats

Calories from protein and fat should be held stable so a drop in carbohydrates on non-training days also coincides with a drop in total calories.

Some arguments for adopting such a strategy include;

1 - By ensuring there are more low calorie/carb days than high calorie/carb days we can keep our body in the calorie deficit required for sustained fat loss.

2 - Intermittent bouts of higher calories and carbs can help offset any slowing down in our metabolic rate which can occur during a consistently low calorie meal plan.

3 - High intensity exercise drains our muscles of glycogen so they will readily soak up the extra carbs consumed on workout days before they can get stored as body fat.

4 - Higher calories and carbs encourages better recovery from our workouts which helps preserve valuable muscle tissue thus prioritising fat loss over weight loss.

5 - Reducing carb intake on non-workout days can help lower the concentrations of insulin in our bloodstream which encourages the mobilisation of stored body fat for energy.

6 - Protein is the most satiating of macronutrients. By dropping carbs and keeping protein and fat stable we can eat fewer calories without suffering the hunger which derails so many a meal plan.

7 - Higher calorie and carb days can provide a satisfying psychological reward following days of restricted low carb eating. Knowing these refeed days are looming can provide the extra bit of encouragement we need to stick with our plan.

So is carb cycling for everyone? Of course not. It’s simply one of many tools we can use to attack our physique and fat loss goals. As with anything it will work more effectively for some than others.

For example during the early stages of a fat loss program when we have a lot of weight to lose focusing on advanced strategies like carb cycling is overkill. The risk of metabolic slowdown or muscle loss is greatly reduced when our body is carrying a lot of extra weight so our focus should be directed towards building simple and sustainable eating habits which allow us to seamlessly reduce the total caloric load of our diet.

Over time the rate at which we lose weight will plateau which provides a good indicator a new strategy is needed to kick-start the final sprint towards a more aggressive body-composition target. I discussed the drawbacks of obsessing over extreme leanness in the previous article but carb cycling is one way to provide just such a boost.

Downsides to the strategy include the potential for an own goal. Abusing higher carb days by feasting from dawn until dusk and massively overdoing total calories can and will undo previous fat loss efforts. Carb cycling is not an excuse for an all-you-can-eat party!

Last but not least there will be people who respond well to lower carbohydrate intakes and people who don’t. We all have a unique biochemical fingerprint and this should be respected. Poor mental focus, irritability and low energy are all signs our body may not be responding well to multiple low-carb days and our strategy may need a rethink.

There is a lot we can learn from nature in our quest to stay lean, strong and healthy. Varying our caloric intake is one such lesson and with the added twist of carb cycling it can provide the fat loss breakthrough we need when our basic strategies start to fail.