The National Institute of Diabetes and Digestive and Kidney Diseases notes that one in three adults are overweight, two in three adults are considered overweight or obese — with one in 13 considered to have extreme obesity.
Overweight status, based on body mass index, a measure of body fat tied to height and weight in adults, is a BMI of 25 to 29.9 — with the obese state at 30-plus— 40-plus yielding to extreme obesity.
Research, Pretreatment Fasting Glucose and Insulin as Determinants of Weight Loss on Diets Varying in Micronutrients and Dietary Fibers — The Pounds Lost Study, appearing in the March issue of the online journal Nutrients, emphasizes that over the last 30 years, there has been “a great deal of controversy about the composition of the optimal diet for weight loss and maintenance.”
From the modified, low carbohydrate, high protein Atkins’ diet, named for its originator Robert Atkins MD, to the other end of the diet spectrum with Nathan Pritikin’s high carb, low fat eating strategy, and most recently the Paleo and its Ketogenic cousin, the appropriate dietary weight loss strategy can be quite challenging.
The Pounds Lost researchers, which includes members from the Pennington Biomedical Research Center in Baton Rouge, comment that “efforts to identify a preferable diet for weight loss and weight loss maintenance based on macronutrient composition have largely failed, implying that no single diet is ideal for all participants with overweight and obesity.”
For instance, in January of 2018, Jamanetwork.com (Journal of the American Medical Association) stated “a meta-analysis of 13 randomized controlled trials suggested that people on ketogenic diets tend to lose more weight and keep more of it off than people on low-fat diets.”
The Jama network concluded that “the appetite-suppressing powers of the (keto) diet aren’t fully understood but could have to do with the satiating properties of fat and protein, changes in appetite regulating hormones on a low-carb diet, a direct hunger-reducing role of ketone bodies — the body’s main fuel source on the diet — or other factors.”
Pennington researches analyzed data from the Pounds Lost trial, “to investigate whether FPG (fasting plasma glucose) and FI (fasting insulin) are prognostic markers for long-term weight loss in four diets differing in carbohydrate, fat and protein content, and assess the role of dietary fiber intake.”
The Pound Lost study recruited 811 overweight adults, who were randomized over 24 months to one of four energy-reduced diets (deficit of 750 kcal per day from baseline) — varying in macronutrient composition. The dietary objectives for all groups were to obtain at least 20 g of dietary fiber per day — using low glycemic carbohydrate sources, such as sweet potato and cruciferous vegetables.
The nutrient goals for the four diet groups included:
- 20% fat, 15% protein and 65% carbohydrates — low-fat/average-protein.
- 20% fat, 25% protein and 55% carbohydrates — low-fat/high-protein.
- 40% fat, 15% protein and 45% carbohydrates — high-fat/average-protein.
- 40% fat, 25% protein and 35% carbohydrates — high-fat/high-protein.
The study participants had baseline and 24-month assessments of FPG, FI, height, weight, insulin resistance status — with six and 24-month dietary recalls from telephone interviews of 50% of the participants — with diabetes being an exclusion factor.
The analysis identified “modest differences in diet-specific weight loss between glycemic phenotypes,” such that individuals with a normal blood glucose level “could benefit the most from low-fat/high-protein diets, subjects with prediabetes (and low insulin) could benefit the most from diets high in dietary fiber and subjects with insulin resistance could benefit the most from high-fat/high-protein diets.”
Using the study conclusion, it makes sense before you start a weight-loss diet to consult with your primary care provider to establish a baseline body composition assessment, blood glucose and insulin status — along with additional assessments to rule out insulin resistance.
Mackie Shilstone, a regular contributor to NOLA.com | The Times-Picayune, has been involved in the wellness sports performance industry for 40 years. He is currently a fitness consultant to Serena Williams, has trained more than 3,000 professional athletes, consulted a litany of professional sports franchises and volunteers his time to train members of an elite U.S. Special Forces Unit and the NOPD. Contact him at mackieshilstone.com.