deficit cycling for fat loss

When I talk to bodybuilders and others that want to lose fat, or increase muscular definition for competition purposes, I often hear them ask about things like re-feeds and cheat days.

Re-feeds and cheat days are generally defined by the bodybuilding community as days of extra carbohydrates and/or calories over and above typical daily calorie intake. Some people will choose to make this a free-for-all – eating whatever they want for one meal or even all day. On the other hand, some will simply eat the same foods they normally eat, but eat them in greater quantities.

This general concept can be used advantageously however it’s important to first understand the process of fat loss before I describe a similar strategy I refer to as “Deficit Cycling” which may be beneficial when incorporated within a more comprehensive nutrition and training program.

Fat Loss 101
To be converted into a usable form of energy, fatty acids must undergo a process called beta oxidation. When we use energy we say that we are burning calories. But burning calories is simply a series of metabolic reactions. The eventual purpose of these reactions is to produce Adenosine Tri-phosphate (ATP), a molecule that stores energy until it can be released to power the body.
Fat loss occurs through a process called lipolysis, which is also known as the breakdown of stored fat. In order to induce lipolysis, you need to create an energy deficit or, in simpler terms, burn more calories than you consume from foods. This can occur by eating less, adding physical activity, or in many cases a combination of both. Stored fat will be used to produce energy whenever your body runs out of energy from the foods you eat. The entire idea of weight loss is founded upon this basic premise.

Negative effects of energy deficit
However, if you restrict calories for too long or too much it can lead to negative changes in how your body burns calories and result in a disruption of the hormones that regulate our food intake and body weight. This may lead to a slower rate of calorie burning as well as increased hunger.

In order to offset this, I will typically recommend incorporating brief periods of lower calories combined with cardiovascular exercise to yield reasonable fat/weight loss. While this generally results in a slower rate of weight loss, it may help eliminate any unfavorable changes that lead to slower metabolism and/or loss of muscle tissue. And, since lean muscle mass is your predominant calorie burning furnace, any losses in lean muscle mass would further contribute to a reduced rate of calorie burning and hinder long-term progress.

Cycling Carbohydrates and Cardio Exercise 
A recent study suggests that most but not all bodybuilders during the contest phase of training may respond best to consuming @1g -1.25g/lbs. of lean body mass per day of protein, and 15-30% of calories from fat, with the reminder of calories coming from carbohydrate. (Helms et.al. 2014) This is in general agreement with what most research supports.

Therefore, once protein and fats are adjusted within reasonable range of the aforementioned levels, I recommend cycling the amount of calories (usually in the form of carbohydrate) as well as the amount of cardiovascular exercise. The idea here is periodically to tap stored fat by burning more calories than you consume and then subsequently increase calories back to weight maintenance levels or even slightly above your baseline. 
The effect is similar to what is referred to as re-feeding as described earlier or what some call carb cycling. Research shows that a short term increase in metabolism results from a brief period eating above your baseline calories – ideally by increasing total daily carbohydrate intake. But rather than incorporate free-for-all cheat days, I prefer to be a little more meticulous by continuing with the same food choices, and planning and measuring the appropriate quantities.
It’s also important to note the amount and need for carbohydrates can be highly variable between individuals and reducing carbohydrates too low can hinder the ability to train intensely, so it’s important to pay close attention to strength and energy levels as well as any changes in lean mass. Eating higher amounts of carbohydrates can also help maximize glycogen (carbohydrates stored in muscle) as well as control hunger.
This is why I recommend the amount of calories from carbohydrates as well as cardiovascular exercise coincide with the demands of training performed on each given day. Training bouts requiring higher energy may require higher calories in the form of carbohydrates and/or a reduction of cardiovascular exercise.

For example, assuming you have four strength-training workouts per week, you might incorporate higher carbohydrates and reduce or eliminate cardiovascular exercise on the days of your two most demanding workouts. On the days of your easier workouts you might incorporate medium carbohydrates and/or add a modest amount of cardio, and on off-days you’d consume low carbohydrates in conjunction with some additional cardiovascular exercise.
Although it’s necessary to burn more calories than we consume in order to create weight loss and fat loss, extended periods or excessive energy deficits can lead to a sluggish metabolism and have negative effects on body composition. Incorporating a simple strategy consisting of cardiovascular exercise combined with carbohydrate cycling may serve as a viable alternative for individuals seeking longer-term progression of fat loss, maintenance of lean muscle mass and improvement of overall body composition

Train Smart and Good Luck!

Vic Tringali earned a Bachelor of Science in Exercise Science from Salisbury University and a Master of Science in Exercise Science from California University. He holds multiple nationally-accredited health and fitness-related certifications, including specialties in Strength and Conditioning, Performance Enhancement, and Personal Fitness training.

From 2000-2007 he was a 5-time National Finalist at the NPC National Bodybuilding Championships and NPC USA Championships. He continues to support the bodybuilding community as a professional judge for the National Physique Committee (NPC) and also maintains a private practice (Team Vic Exercise Science) offering coaching and consulting to numerous professional and national-level body builders, physique and figure competitors.
For more information visit http://www.teamvic.com