The dangers of New Year’s Diets for the Elderly

My joy in celebrating a New Year is often dampened by the absolute onslaught of advertisements and resolutions featuring diet products claiming to extend your life, improve your social life, etc.  The amount of science behind those claims is debatable at best, and perhaps even dangerous for us old folk.  The trillion dollar diet industry has everything to gain by getting us to buy their products, and money is a welcome excuse to ignore the science. Here’s the truth, with a couple of scientific articles tossed in:

  1. Folks, we are all going to die, but BMI is not a good predictor of lifespan in the elderly. In fact, a BMI of 31.7 is categorized as morbidly obese but in the over 70-cohort is the BMI least associated with mortality.  Furthermore, “a broad range of BMIs are well tolerated by older adults.” Read the article for yourself. A second article goes a bit further to say that “Low BMI and weight loss are risk factors for mortality in the elderly and smoking habits did not significantly modify that relationship. The BMI ranges with lowest risks for 15 y mortality are relatively higher in elderly.” A 2017 Chinese study reiterates “Among older persons aged 65 and above, the overweight-or-obese category of BMI was not associated with excess all-cause mortality.”
  2. Weight loss is common in the elderly, as we get shorter and our systems become increasingly less efficient and less responsive to various feedback loops associated with aging.  It’s not a bad thing to enter old age with a little extra weight, in preparation for illness or normal aged weight loss. Read the article about normal weight loss in the elderly here,
  3. Finally, excess weight may actually be preventative in bone mineral density (BMD) loss.  Body composition (lean mass, fat mass, and soft tissue mass) in older men is positively associated with BMD at all sites of the body (arms, legs, and trunk).

Thanks for allowing me to vent, though I could go on talking about the serious risks of yo-yo dieting to cardiac health, the probability that weight loss won’t endure in most, and the reduction in injury for overweight elders who fall (as we all will).