T Nation

Radical 4-Day Fat Loss Study, Interesting

I don’t think I would have the drive to do it, but take a look at this.
Calbet, JA et. al. A time-efficient reduction of fat mass in 4 days with exercise and caloric restriction. Scand J Med Sci Sports. 2014 Mar 6. doi: 10.1111/sms.12194.

subjects weight stable for at least 3 months, all between 20-40% BF, age 18-55
5 phases–phase 1, normal activity, phase 2, 4-day intervention (the actual fast), phase 3, 3-days of a normal diet and limited activity, Phase 4 was four weeks where subjects could eat and exercise by their own choice and Phase 5 was a one year follow-up.

phase 2 was the meat of the experiment. severe calorie restriction and lots of exercise. subjects were given 3.2 kcal/kg (1.4 kcal/lb), appr a 90% deficit. (DAMN) AND they did arm crank exercise for 45 minutes and walked for EIGHT hours. Real low intensity (DOUBLE DAMN) The calories were either all protein or all sucrose. OK, only 4 days but holy crap.
The results?

                            Fat Loss	          LBM Loss 

Phase 2 (4 days) -2.1 kg (-4.6 lbs) -2.8 kg (-6.2 lbs)
Phase 3 (3 more days) -2.8 kg (-6.1 lbs) -1.0 kg (-2.2 lbs)
Phase 4(4-week Follow up) -3.8 kg (-8.4 lbs) -0.5 kg (-1.1 lbs)
Phase 5 (1-Year Follow up) -1.9 kg (-4.2 lbs) -0.4 kg (-0.88 lbs)

weird that there was nearly no difference between the protein only or the sugar only groups. also weird is that the research indicated that the majority of the loss was from the trunk. Might that be because the limbs were active?

Questions for you
Could you do this if you were compensated? (that was my first thought)
2nd, have to wonder if higher calories from quality protein (2x or so allowed in this study) and a big reduction in the work performed would change the amounts or percentages of mass lost.
3rd, for bigguns, the 30+% BF folks, would this be repeatable and effective? 4 days on the “intervention” and a good amount of time on stabilization and recovery? I mean, go after it balls out, long enough to have impact and short enough to not throw everything out of whack, and repeat twice per month? Of course under supervision. OR weekends for a month?
I’m just an insomniac and am still up at 515am Dallas time.

I’ve been reading up recently on a lot of the studies relating to exercise and fat loss. It’s all very interesting (I’m a fellow insomniac :slight_smile: )

I could do this if I wanted to loose weight and I thought it would work. I’m very disciplined for short term stuff. To my mind it’s pretty natural - we will have evolved to cope well with periods of fasting and heavy work load.

Here’s my thoughts based upon the stuff I’ve been reading up on lately:

The ‘lots of exercise’ simply makes the severe calorie restriction even more severe. I guess this approach simply allows you to take in a few nutrients whilst getting almost all energy from muscle and fat stores. I very much doubt that the exercise is what’s causing the muscle loss.

There was a study that showed that provided you did some strength training you wouldn’t loose muscle mass. Even on a severely restricted diet. So perhaps this would work WITHOUT the muscle loss if you simply included strength training (in addition to the cardio). If you had the energy to do so!!!

The fact that they continued to loose lean mass even when eating and training normally suggests that they need to do more strength training - not just during the fasting stage, but long term.

My guess is that it could work well as you suggest - a periodic fast. Maybe more like once a month though? Provided more strength training was included (in addition to the cardio).

One quick observation: they lost lean body mass, that does NOT have to mean muscle tissue. When eating only 300-400 calories a day for 4-7 days while exercising you will have depleted all your glycogen and with that much of the water that the glycogen helps hold inside the muscle.

Losing 3-6 lbs of water accounts for the LBM. 4-7 days of very low calorie dieting will not make you lose a lot of muscle, especially since they are still ‘exercising’.

I would be curious to see similar studies. Yes with SOME strength training. Brief Intense Frequent while on something like this. I don’t think it would stop it but it would minimize it. Heck wasn’t there a study that should just to maintain strength a very small amount of work needed to be done.
Take a look at bulletproof fasting.

Kinda wicked. Can’t me me gnawing on butter only.