The incidence of obesity has been rapidly
mounting in people causing serious health concerns affecting the heart, mental
health, and even other vital organs such as the kidneys.
A recent study on 'Comparative Effects of Low
Carbohydrate High-Protein Versus Low Fat Diets on the Kidney' discusses
the impact of weight-loss diets on the kidneys in healthy obese patients. Dr.
Allon N Friedman. M.D. Nephrology, the Department of Medicine, Indiana
University, provides Medindia with additional details of the clinical trials.
Obesity, weight loss and kidney related issues are interdisciplinary subjects,
what sparked the interest on the impact of weight-loss diet on kidneys?
Ans. A number of studies have been conducted on
the adverse effects of weight loss diets leading to various complications or
developments. It has been going on for a while, but why they occur and what was
the effect of low-carb high protein diet
on the kidney was not known. There wasn't sufficient information on the
diet's impact on kidney function, which led to the study supported by The
National Institute of Health in the U.S.
After the two years of trial period, were the participants monitored? Was
there a follow up on them to verify that they did not develop any other
Ans. No, there was no follow-up. The
participants were involved within the clinical trial period of two years when
they were supervised and were under the prescribed weight-loss diet. During the
trials there weren't any major complications reported.
years seems like a very short period to monitor kidney functioning. How
applicable are the results of your trial to actual practise?
Ans. True, two years is a short term for
clinical trials and our scope was limited to that period. But we did draw our
inferences from tests on proteinuria, a test conducted to check the amount of
protein present through urine while the participants were on the low-carb high
Ques - A
person may lose weight due to other reasons such as following a regular
workout; diet needn't be the only reason. Do you think that could have had an
impact on your trials?
Ans. Yes, there are many other ways to reduce
weight but our trials focused on diet intervention and the impact of the
weight-loss diet in healthy obese patients and how that in turn affected the
Ques - Was
there any difference between the results in men and women?
Ans. The outcome in men and women were similar. I
can't recall any difference between the way men and women responded to the
People from different ethnic groups have participated in the study. Did the
metabolism differ according to ethnic groups?
Ans. Majority of the
participants were Anglo-American but no major differences were noted during the
study among other ethnic groups.
Ques - Would
the low-carb, high protein diet intended for weight loss, prescribed during the
trial, be applicable to a person with no kidney disorder?
Ques - The participants were healthy obese people and
that's how participants were selected for the trial. What if the person had
diabetes not necessarily as serious as Type 2 diabetes, would the diet still
hold good to lose weight?
Ans. Our trials were conducted on healthy obese
individuals and did not include people with diabetes. But from my professional
experience, I can say that people with diabetes will do well with the weight
loss diet used during the trials.
The healthy obese participants were on a low-carb
high-protein weight loss diet for a period of two years. However the study
agrees that a follow-up will be required to ascertain long-term impact on
kidney function. The study was conducted and consolidated from three centers.
Other authors who contributed to the critical study include, Lorraine G. Ogden, Gary D. Foster, Samuel Klein,
Richard Stein, Bernard Miller, James O. Hill, Carrie Brill, Brooke Bailer, Diane R. Rosenbaum and Holly R. Wyatt.