3 replies to this topic

[vader]

Weight loss is by definition a form of calorie restriction.

 

I've heard that for some people this type of restriction could lead to anorexia by several means (lower zinc, changes in ghrelin secretion).

 

It seems that CR would lengthen lifespan, unless you develop anorexia, then it would severely lower expected lifespan.

[Michael]

Weight loss is by definition a form of calorie restriction.

 
Er ... no it isn't. You can lose weight without restricting Calories at all, by e.g. increasing your activity levels while holding energy intake constant. And there's a distinction between the technical sense in which biogerontologists use "calorie restriction" and the looser sense in which it's used in a weight loss context.
 

I've heard that for some people this type of restriction could lead to anorexia by several means (lower zinc, changes in ghrelin secretion).

 
 If you're practicing CR correctly, you won't lower your zinc: by definition, it's "Calorie restriction without malnutrition." There is some evidence that anorexia may somehow impair zinc metabolism, but you seem to be implying that lack of zinc causes anorexia nervosa, for which I'm aware of no evidence nor theoretical basis. Similarly for ghrelin.

 

IAC, there is direct evidence on this question. Multiple studies have addressed the relationship between CR and eating disorders, and the uniform finding in actual prospective studies is that neither conventional dieting for weight loss in the overweight (1), nor Calorie restriction per se(2), leads to ED. Yet people keep raising the specter of it, and even accusing people working to improve nutrition and combat the obesity epidemic of driving young girls into eating disorders.

 

References
1: National Task Force on the Prevention and Treatment of Obesity. Dieting and the development of eating disorders in overweight and obese adults. Arch Intern Med. 2000 Sep 25;160(17):2581-9. Review. PMID: 10999971 [PubMed - indexed for MEDLINE]

2: Williamson DA, Martin CK, Anton SD, York-Crowe E, Han H, Redman L, Ravussin E; Pennington CALERIE Team. Is caloric restriction associated with development of eating-disorder symptoms? Results from the CALERIE trial. Health Psychol. 2008 Jan;27(1 Suppl):S32-42. PubMed PMID: 18248104.

[vader]

 

Weight loss is by definition a form of calorie restriction.

 
Er ... no it isn't. You can lose weight without restricting Calories at all, by e.g. increasing your activity levels while holding energy intake constant. And there's a distinction between the technical sense in which biogerontologists use "calorie restriction" and the looser sense in which it's used in a weight loss context.
 

I've heard that for some people this type of restriction could lead to anorexia by several means (lower zinc, changes in ghrelin secretion).

 
 If you're practicing CR correctly, you won't lower your zinc: by definition, it's "Calorie restriction without malnutrition." There is some evidence that anorexia may somehow impair zinc metabolism, but you seem to be implying that lack of zinc causes anorexia nervosa, for which I'm aware of no evidence nor theoretical basis. Similarly for ghrelin.

 

IAC, there is direct evidence on this question. Multiple studies have addressed the relationship between CR and eating disorders, and the uniform finding in actual prospective studies is that neither conventional dieting for weight loss in the overweight (1), nor Calorie restriction per se(2), leads to ED. Yet people keep raising the specter of it, and even accusing people working to improve nutrition and combat the obesity epidemic of driving young girls into eating disorders.

 

References
1: National Task Force on the Prevention and Treatment of Obesity. Dieting and the development of eating disorders in overweight and obese adults. Arch Intern Med. 2000 Sep 25;160(17):2581-9. Review. PMID: 10999971 [PubMed - indexed for MEDLINE]

2: Williamson DA, Martin CK, Anton SD, York-Crowe E, Han H, Redman L, Ravussin E; Pennington CALERIE Team. Is caloric restriction associated with development of eating-disorder symptoms? Results from the CALERIE trial. Health Psychol. 2008 Jan;27(1 Suppl):S32-42. PubMed PMID: 18248104.

 

 

If you increase your activity level, then to lose weight you need to consume less calories than expended. I would say losing weight should be considered calorie restriction, because if it would go for extended amount of time, then the body either will compensate (lowering metabolism by lowered thyroid signaling, mostly) or the animal / human will die. So losing weight is low calorie intake, ergo it is calorie restriction. I don't think there is a consensus how low is "low" in calorie restriction, you might as well train like Phelps and eat 8000 calorie a day and still be on CR.

 

I would say, unless someone gorges on wheat germ / bran (and overdoses on selenium), then zinc deficiency is a real concern. So then, you can't say it's calorie restriction with optimal nutrition, but calorie restriction with optimal supplementation. Besides, if you supplement wheat germ or zinc tablets, then your appetite will sky-rocket and make CR a very hard thing to do.

 

Zinc deficiency is indistinguishable from anorexia nervosa. Zinc depletion reduces the size of a rat and makes the eat and drink less (ie. induces CR) [1].

 

Ghrelin secretion does change with anorexia [2] and possibly CR.

 

[1]: http://www.sciencedi...031938484902658

[2]: http://press.endocri.../jc.2002-021669

 

Imho, CR is mostly ghrelin and zinc. The execution part at least, those two are the most important for lowering energy intake along with higher TSH and subsequently lower metabolism.

Edited by vader, 26 October 2015 - 06:35 PM.

[Multivitz]

Anorexia is an imbalance of PEA and L Methionine if memory serves me right. PEA stops hunger feeling, Methionine makes hunger and stomach acids I think. Zinc deficiency and general malnutrition is common. Transmutation is a major part of the picture when fasting