August 18, 2011
Restricting Calories Even While on a High-Fat Diet Improves Health

It is hard to establish behavior changes with many individuals when it comes to diets.  As you know, the westernized diet is high in fat and leads to complications with health.  Every trainer will tell their clients to eat “healthier”.  Well what if we didn’t have to eat healthier for the preservation of our lifespan and well-being?  What if we could just eat slightly less of the bad food and receive improvements in health?  Now all the personal trainers and nutritionists say at once—blasphemy!

Introduction:  Few studies have focused on dietary restriction (DR) of a high-fat diet (HFD) in regards to improvement on health.  This is in fact more relevant to the dietary status of society.  Thus, scientists put mice on a HFD (30% of calories from fat) and restricted their dietary intake to better understand changes in health.

Results:  HF-DR (high-fat diet restricted) mice lost significantly more body weight (which stabilzed after the first 5 weeks) as well as white-adipose tissue depots than mice receiving the high-fat diet but not the restriction in calories.  HF-DR increased their insulin sensitivity as well as significantly lower levels of serum glucose and insulin.  HF-DR also decreased their cholesterol and increased their HDL to LDL ratio.  Finally, the novel technique of gene array analysis discovered significant increases in gene expression for genes involved in lipid metabolism and mitochondrial functioning.

Conclusion:  “The results of the study prove that DR can reverse the adverse effects of an initial unhealthy HF diet. Our treatment had a large influence on gene expression in WAT.  It is hypothesized that the restriction procedure has forced the metabolism of mice toward the utilization of lipids in order to effectively make use of the diet, spare carbohydrates, and to create a stable energy balance.”

My input:  Now don’t jump to the conclusion that I’m saying it is okay for individuals to keep eating poorly but eat less of it if they want to improve their health because I assure you, I’m not.  However, if you are having trouble with a client who won’t change their diet, why not just suggest eating less to start?  That way, when they lose weight initially (as the mice did in the first 5 weeks) they are receiving health benefits and you can then try to get them to change their eating habits by instructing them this will help them lose even more weight.  It is at this moment when individuals become weight stable that it is most vital for an intervention in their lifestyle.  My major critique is that the diet the researchers used consisted of 30% fat which may be kind of low for the everyday sedentary person even though the authors claim they used values similar to human western diets.  They note that studies with fat intakes as high as 55-65% did not show similar improvements in health.  However, I still like the findings of this study and think it is very practical to those who personal train and/or give nutrition/diet advice.  Well done.

Duivenvoorde et al J Mol Endocrinol. 2011 Aug 3;47(1):81-97.

April 30, 2011
Reasonable Quantities of Red Pepper May Help Curb Appetite, Study Suggests

"We found that consuming red pepper can help manage appetite and burn more calories after a meal, especially for individuals who do not consume the spice regularly," said Richard Mattes, distinguished professor of foods and nutrition who collaborated with doctoral student Mary-Jon Ludy. 

Click to read more.

March 28, 2011
Lifespan

Did you know that the only proven intervention that increases lifespan across species, including primates, is calorie restrictionCalorie restriction is defined as a reduction of 25-40% in the calorie intake when fed ad libitum, without reaching malnutrition.  Most theories to date agree that improved mitochondrial metabolism is key for the beneficial effects of calorie restriction.

 

Colman, R. J., R. M. Anderson, S. C. Johnson, E. K. Kastman, K. J. Kosmatka, T. M. Beasley, D. B. Allison, C. Cruzen, H. A. Simmons, J. W. Kemnitz, and R. Weindruch. Caloric restriction delays disease onset and mortality in rhesus monkeys. Science. 325:201-204, 2009.

Yu, B. P., E. J. Masoro, and C. A. McMahan. Nutritional influences on aging of Fischer 344 rats: I. Physical, metabolic, and longevity characteristics. J Gerontol. 40:657-670, 1985.

February 6, 2011
Identification of Adipocyte Genes Regulated by Caloric Intake

 The aim of the study was to identify adipocyte genes regulated by changes in caloric intake independent of alterations in body weight.  Using a significance level of P < 0.05 for all comparisons, 52 genes were down-regulated, and 50 were up-regulated by caloric restriction and regulated in the opposite direction by refeeding and overfeeding. Among these were genes involved in lipogenesis (ACLY, ACACA, FASN, SCD), control of protein synthesis (4EBP1,4EBP2), β-oxidation (CPT1B), and insulin resistance (PEDF, SPARC).  Metabolic genes involved in lipogenesis, protein synthesis, and insulin resistance are central in the transcriptional response of adipocytes to changes in caloric intake.

Franck et al 2011 J Clin Endocrinol Metab, Vol. 96 (2): 413-418