So, what you're saying, is that I can MAYBE (depending on predisposition to personal response) increase my REE by a whopping 70kcal a day (on a roughly 5000-6500 kcal a day intake) by going to a VLCD?
The humor of the lowered cortisol levels in the low-fat group isn't lost on me, though. That's hilarious.
I'm surprised to see the T3 levels dropping on a VLCD. I wouldn't have expected that.
I'd like to see this followed up in a long-term study, and one of the options being to test high-glycemic foods given in the post-training hours. I honestly have grown a religious affinity for following up heavy training by consuming over 90% of my daily sugars in the 2 or so hours after working out. Seems to work well for me. Then again, I'm not one to spout the glorious wonders of any diet.
Perhaps I will change my original stance of "a calorie is a calorie" to "a calorie is a calorie, give or take 1-2%."
As far as T3 goes, I'm not in the least bit surprised. With leptin dropping due to the very low carb nature of the diet, TSH and T3 go down while cortisol goes up. It's a shame they didn't measure testosterone and growth hormone levels: those probably would have been the worst on the VLCD, too.
Now, this was only done at maintenance which takes a way some of the issues that come with being completely Calorie restricted, thankfully. It's then something to think about, though, that if you're going to maintain this sort of diet, you can expect those hormonal issues to be a regular thing. It's one thing if this were temporary because it's simply a fat loss diet, but using it as a maintenance diet brings a different mentality.
On that note, the metabolic issues (HDL and insulin sensitivity, mainly) would be of a concern to me. But here's how I see it:
Those who have the biggest concern over metabolic issues tend to be pre-diabetic, diabetic, and/or quite overweight. Their first and major concern is weight loss, for ALL sorts of reasons. How they go about it doesn't really seem to matter
; the weight loss in and of itself improves all sorts of health markers.
This study proves just that as well. Like I said, all of the dieters improved insulin sensitivity from simply having lost weight. How they maintained that weight affected the degree of sensitivity (with the VLCD having the best), but they all improved from their pre-diet baselines. But, the average weight of the subjects at the start of the study was 105 kilos or about 231 pounds. They lost weight until they had lost an average of 12.5% of their bodyweight. This means, on average, they ended up around 200 pounds. (The average height was about 5' 8", by the way).
It'd be safe to say that they all could benefit from continuing to lose more weight, regardless of the approach needed to do so. To what degree the insulin sensitivity could continue to improve could be remarkable, or cap off very quickly. This would shed light on what would be needed from that point. Get them to a weight range that's generally recognized as healthy, then we can worry more about the best possible maintenance approach.
And yet another side point: the activity used. Couldn't find specifics, but the MPVA (moderate- to vigorous- physical activity) came out to about 10 to 15 minutes per day. Now, I don't know about any of you on here for sure, but for those of you who lift weights or perform strength training in one capacity or another, I think I'd be hard-pressed to find someone who only does that much. Point being, the amount of strength training (if ANY) that was done during this study was minimal. This again is important for two reasons
1)Better muscle preservation (in this case, the lack thereof)
2)The ability to perform high intensity activity.
The VLCD had the lowest MPVA per day @ about 10 minutes, while the low-fat had the highest @ about 15 minutes. This was spun by Taubes in his NY Times article to basically say, "See! My low-carbers didn't even NEED to workout that much to get the same Calorie burn. It's obviously superior." But consider this: the VLCD had less vigorous activity because they couldn't sustain it and perform the same way the low-fat or low-GI could. More food for thought..
So as far as metabolic adaptations go, the first concern is usually weight loss in and of itself. Though, for large individuals with a LOT of weight to lose, VLCD weight loss diets
seem to do best with them.
-They don't have the ability, inclination, or strict need to do activity that requires carbs.
-They see a more immediate response of regulating their out-of-whack blood sugar
-They see a larger drop in weight very quickly from the water loss along with the fat loss (and that can be psychologically very helpful - imagine needing to lose 50-100 pounds and being told you can only lose a pound or two a week; contrast that with losing 20 pounds in your first 2 or 3 weeks. Water or not, it helps psychologically give them positive feedback which helps a lot with adherence)
-They cut out a lot of foods that seem to be trigger foods.
-They tend to actually start eating their fruits and veggies. By telling them they only get 50-75g of carbs per day, they can only really achieve this by getting a lot of veggies with some fruit. If they're allowed more (like 200-300g per day), they'll stick with the tastier, starchier, more sugary stuff and forget about the fruits and veggies.
So I'm all for VLCDs in people that meet those criteria. But, outside of that, low-carb diets tend to start to do really shitty things for everyone else.
When we consider the hormonal impact, it doesn't seem wise trying to maintain a diet that has leptin plummeting, making TSH, T3, likely testosterone and growth hormone drop and cortisol elevate. This same diet doesn't allow for any sort of performance in the weight room, or parkour for that matter for any of the power moves. You can get some balance and other low-intensity work in, but good luck performing high intensity movements.
And suffering through all of this so you can get a possible increase of resting energy expenditure of about 70 kCals per day (and like Joe points out, many of us are eating far more than 3000 kCals per day... or at least should be).... sounds like the worst possible choice you could make.
I'm with Joe in wanting to see a study looking at some sort of cyclical carb eating approach used, preferably under conditions of weight loss, weight maintenance, and weight gain. And including weight training. But I also would like an all-expenses-paid vacation on a cruise ship.
And the latter is more likely to happen.