Back in 2012, David S. Ludwig, MD, PhD, and
colleagues at New Balance Foundation Obesity Prevention Center (Harvard), and
Children’s Hospital, Boston, and Brigham and Women’s Hospital, Boston, and
Baylor College of Medicine, Houston, and Vanderbilt University, Nashville,
published the results of a well-designed, four-year study in June 27 issue of the
Journal of the American Medical Association (JAMA). The purpose was to study “the
effect of dietary composition on energy expenditure during weight-loss maintenance
“(my emphasis).
Three days later the New York Times published an opinion piece, "What Really Makes
Us Fat," loosely based on the study. In it, award winning science writer
Gary Taubes, said, “What was done by Dr.
Ludwig’s team has never been done before.” He concluded his piece with, “The public health implications are enormous.”
(emphasis added)
The study began after all subjects had achieved a
10% to 15% weight loss by a calorie restricted (60%) “run-in” diet. Then, each
for 4 weeks, the participants ate three isocaloric (2,000kcal/d) diets: 1) a low-fat
diet (60% carbs, 20% fat, 20% protein, high glycemic load); 2) a low-glycemic
index diet (40% carbs, 40% fat and 20% protein, moderate glycemic load); and 3)
a very-low carb (Atkins) diet (10% carb, 60% fat and 30% protein, low glycemic
load).
The JAMA authors concluded: “Our study
demonstrates that commonly consumed diets can affect metabolism and components
of the metabolic syndrome in markedly different ways during weight-loss maintenance,
independent of energy content. The low-fat diet produced changes in energy
expenditure and serum leptin that would predict weight regain. In addition, this conventionally recommended diet had unfavorable effects on most
of the metabolic syndrome components studied herein. In contrast, the very low carbohydrate diet had the
most beneficial effects on energy expenditure and several metabolic syndrome
components…” (HDL & triglycerides), emphasis added by me.
Energy expenditure, the primary outcome measure
of the study, was measured by state-of-the art stable isotope analysis at
Baylor. This outcome was especially stunning: “The results of our study
challenge the notion that a calorie is a calorie from a metabolic perspective,”
the authors stated. “TOTAL ENERGY
EXPENDITURE DIFFERED BY APPROXIMATELY 300 KCAL/D BETWEEN THESE 2 DIETS” (VERY
LOW CARB AND LOW FAT), “AN EFFECT CORRESPONDING WITH THE AMOUNT OF ENERGY…EXPENDED
IN 1 HOUR OF MODERATE-INTENSITY EXERCISE.”
In other words, as Taubes explained, “…when the subjects were eating low-fat
diets, they’d have to add an hour of moderate-intensity physical activity each
day to expend as much energy as they would effortlessly on the very-low-carb
diet. And this while consuming the same amount of calories. If the physical
activity made them hungrier – a likely assumption – maintaining weight on the
low-fat, high-carb diet would be even harder,” Taubes wrote.
Taubes then posited, “If we think of Dr. Ludwig’s subjects as pre-obese, then the study
tells us that the nutrient composition of the diet can trigger the
predisposition to get fat, independent of the calories consumed. The fewer
carbohydrates we eat, the more easily we remain lean. The more carbohydrates,
the more difficult. In other words, carbohydrates are fattening, and obesity is
a fat-storage defect. What matters, then, is the quantity and quality of
carbohydrates we consume and their effect on insulin.” These five sentences
say it better than a whole book!
Ludwig’s subjects are, frankly, “pre-obese.” As
the study states, “only 1 in 6 overweight and obese adults report ever having
maintained weight loss of at least 10% for 1 year.” Taubes reasonably says Ludwig’s
subjects are “almost assuredly going to get fatter, so they can be research
stand-ins for those of us who are merely predisposed to get fat but haven’t
done so yet and might take a few years or decades longer to do it.” Does this
sound like you?
Taubes then concludes, “From this perspective,
the trial suggests that among the bad decisions we can make to maintain our
weight is exactly what the government and medical organizations like the
American Heart Association have been telling us to do: eat low-fat,
carbohydrate-rich diets, even if those diets include whole grains and fruits
and vegetables.” NOTE BENE: “…EVEN IF
THOSE DIETS INCLUDE WHOLE GRAINS AND FRUITS AND VEGETABLES.”
Your choice: Eat Very Low Carb, or eat whole
grains, fruits and vegetables and exercise 1 hour a day to burn them off.
No comments:
Post a Comment