The Myth of Starvation Mode

2012party

http://stunteating.com/2010/06/02/the-myth-of-starvation-mode/

Thoughts on this blog post? I found it very helpful (provided there's truth to it)....

Method_One

I believe the article has some good points. Your not going to starve to death if you're overweight and in a calorie deficit for an extended period of time. It's my understanding that a significant decrease in calories will reduce the resting metabolic rate (RMR). It makes sense, if you're underfeed you will naturally not be inclined to walk to the store, or fidget on the couch.

Looking around on the net I found:

"Resting metabolic rate, body composition and thyroid hormones. Short term effects of very low calorie diet.
Cavallo E, Armellini F, Zamboni M, Vicentini R, Milani MP, Bosello O.

Abstract
27 obese women (relative body weight 191 +/- 27%), aged 35 +/- 11, underwent a 15 day very low calorie diet (VLCD: 1337 kJ/day). Mean body weight loss was 6 +/- 1.5 kg. Resting metabolic rate (RMR), measured by indirect calorimetry, showed a significant decrease both in absolute values (from 1793 +/- 225 to 1569 +/- 231 kcal/day; P less than 0.001), and in keal/kg body weight/day (from 17 +/- 2, to 16 +/- 2, P less than 0.001). Serum triiodothyronine (T3) significantly decreased from 1.1 +/- 0.2 to 1 +/- 0.2 microgram/1 (P less than 0.001). Before VLCD the differences between measured RMR and theoretical RMR (RMR-T) were not significant. After VLCD RMR values were significantly (P less than 0.001) lower than RMR-T. It was concluded that fat-free mass loss, combined with periferic thyroxin (T4) reduced monodeiodination in its more active form mainly due to low calorie intake T3 could be responsible for the important reduction observed in the resting metabolic rate."

So these guys took 27 obese women and feed them 319 cals/day (converted for kj's) for 15days. They lost 13lbs of total mass and had a 224 cal/day reduction in their RMR, not too bad of a dip in RMR considering the15 days of hardcore calorie deficit. The reduction in T3, a thyroid hormone, will reduce body temp, growth hormone secretion, rate of protein synthesis, etc and may be the reason for the decrease of RMR (low cal+time=low T3=lower metabolic and anabolic function).

This is where the intermittent fasting and alternate day fasting techniques may be useful. You can run pretty good average calorie deficits but still have enough calories during your feeding periods to keep your RMR and hormones chugging along. I've heard it referred to as controlled periods of catabolic fat loss and anabolic refeeding windows where you engage in exercise etc.

Quick note: If you are going to be going low calorie for an extended period of time you will loose muscle and may want to look into supplementation the amino acid Leucine to keep muscle protein catabolisim down.