Calorie Shifting – Improvement to Traditional Calorie Restriction?

In our attempts to rid ourselves of excess body fat, I’m sure we’ve all heard of about a million different dietary designs guaranteed to provide the best dieting experience. And, as we all know by now, it is the energy balance that dictates the end result. In other words, if you consume less than you expend then you will lose mass – this is just the simple laws of physics at work (thermogenesis).

Now, although maintaining a negative energy balance is always going to yield results, there is actually some really interesting research coming out lately demonstrating that a calorie “shifting” approach may actually produce superior fat loss as compared to the more traditional static calorie restriction diets (simple energy in versus energy out style). Here is one I was looking at the other day (1).

In a nutshell, two groups of subjects were compared – a calorie shifting (CSD) and calorie restriction (CR) group.

Study Design
– Four Weeks Control Period (eating at TDEE)
– Six Weeks Calorie Shifting or Calorie Restriction
– Four Weeks Follow-Up

The CSD Group (repeated in four “cycles”)
11 days 1365kCals/day (85g PRO / 187g CHO / 30g FAT)
3 days 1971kCals/day (98g PRO / 271g CHO / 54g FAT)

The CR Group
14 days 1186kCals/day (74g PRO / 163g CHO / 26g FAT)

Despite the fact the CSD group was consuming more total kCals during those 14 days, at the end of the six weeks gross weight loss was nearly identical. However, the amount of fat mass loss was significantly higher in the CSD group. This means that lean mass was better preserved on CSD in addition to the superior fat loss. Also, RMR was significantly lower in the CR group as compared to when they started the trial however RMR was nearly unchanged in the CSD group.

Adherence to the CSD was also higher so it may be easier to get dieters to follow this regimen in “real world” scenarios. They have also replicated this same dietary strategy alongside caffeine supplementation (2). Caffeine has been shown to have the ability to decrease weight through the increase in thermogenesis and fat oxidation rates (3)(4).

Now, the study design wasn’t perfect…body composition was measured using bioelectrical impedance analysis (BIA) which has been shown to be less than perfect. Also, the subjects in both trials were obese and sedentary individuals – I am unaware of a similar study done on well trained athletes though.

With that said, I’ve been testing this out on some of my clients over the last year or so and, across the board, the calorie shifting produces a more pleasant dietary experience along with increased lipolysis. It is even more pronounced on females, in my experience…I find that it is always ideal to take what science tells us and see if it can be replicated with real-world results. So far, the results have been very promising.


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