This commentary is from our highly respected Dr. Stephan Chaney
In several of my previous
emails I have highlighted studies comparing the low fat
and low carb diet plans.
You may recall that by year 1 or 2 (depending on the
study) there wasn’t any significant differences in
weight loss between the two diets.
But, the really discouraging finding from all of those
studies was that 12 months later the patients had
gained back most of the weight that they had lost in
the first place – even when behavior modification was
included as part of the weight loss program.
Recent research has shown that loss of lean muscle mass
was probably at least partially responsible for the
dismal long term success of both the low carb and low
Traditional diets (both low fat and low carb) don’t
provide enough protein to prevent loss of muscle mass.
Once you’ve lost muscle mass your metabolic rate
And, if your metabolic rate is low, it becomes an
uphill battle to keep the weight off – even with the
best behavior modification strategies.
Exercise helps, but exercise alone can’t prevent the
loss of muscle mass if you’re not getting enough
protein from your diet.
So what if you focused on higher protein diets? Could
you prevent that loss of muscle mass?
The answer is a resounding YES!
I’ve told you about Dr. Layman’s ground-breaking study
showing that high protein weight loss diets providing
around 10-12 g of the branched chain amino acid leucine
actually preserve muscle mass.
This week I’m going to bring you up to date on his
You may recall that Dr. Layman compared a high protein,
low fat diet (40% carbohydrate, 30% protein, 30% fat)
with a traditional low fat diet (55% carbohydrate, 15%
protein, 30% fat)
(Layman et al, J. Nutr., 133:
The high protein diet was designed to
provide 10-12 g of leucine/day, while the low fat diet
provided 2-3 g/day
(Layman & Walker, J. Nutr., 136:
The initial study showed that the high protein/high
- promoted retention of muscle mass and preferential
loss of fat mass compared to the low fat diet.
- gave greater satiety (less hunger) and more energy
than the low fat diet.
These results were very impressive, because this was
the very first weight loss diet that had been shown to
preserve muscle mass. However, Dr. Layman didn’t just
rest on his laurels.
The initial study involved just the diet alone, so he
followed up with a study to see what would happen when
you combined the diet with an exercise program.
That study showed that exercise also promoted retention
of muscle mass and loss of fat mass, and that the
effects of exercise and the high protein diet were
additive (Layman et al, J. Nutr., 135: 1903-1910,
In short, exercise makes a good diet even better. No
The initial study didn’t fully examine how the high
protein diet affected risk factors for heart disease
and diabetes, so he followed up with a study to look at
those risk factors (Lasker et al, Nutr. & Metab. 5:30
(November 7) 2008).
That study showed that the high protein diet:
- gave a greater reduction in triglyceride levels, a
greater increase in HDL levels and a greater reduction
in the triglyceride/HDL ratio than the low fat diet.
- gave improved insulin sensitivity (as measured by the
increase in blood sugar and insulin in response to a
test meal) compared to the low fat diet.
The low fat diet initially gave a greater reduction in
LDL cholesterol levels than the high protein diet, but
that effect had completely disappeared by 12 months.
In short, the high protein diet has all of the
metabolic benefits of the low carb diets, but without
the unhealthy fats!
Finally, the initial studies had been short term (10
weeks to four months) with relatively small groups, so
he followed up with a large, multi-center trial that
followed people on the high protein and low fat diets
for 12 months (Layman et al., 139: 514-521, 2009).
This study showed:
- All of the advantages of the high protein diet were
maintained for the full 12 months.
- A significantly higher number of participants were
able to stick with the high protein diet for the full
12 months because it filled them up and gave them more
energy than the low fat diet.
- A higher percentage of participants on the high
protein diet were able to lose a significant amount of
weight (>10%) and keep it off.
At this point, the data are pretty compelling.
If you want to loose weight:
- ignore all of those fad diets. They are not really
backed by solid clinical evidence.
-ignore the debate about low carb versus low fat. If
you’re not getting the protein you need, neither one is
likely to help you in the long run.
Look for a diet that is as close to the high protein,
high leucine diet that Dr. Layman has pioneered and
couple it with exercise and lifestyle changes for