by Dr. Steve Chaney, PhD
However, there are some nutrients such as leucine that
are important for long term weight control and whose
role in weight control is based on solid science.
But, let’s start with the problem before I discuss the
The problem is that whenever we lose weight we generally
lose muscle mass as well as fat. To be precise, you
lose about 5 pounds of muscle for every 12 pounds of
That is a concern because muscle is metabolically much
more active than fat. Since each pound of muscle burns
about 50 calories a day, that 5 pounds of muscle you
lost costs you 250 calories a day.
That means that if you want to keep losing weight at
the same rate after you have taken off that first 12
pounds, you will need to reduce your calories by
another 250 calories a day – and if you manage to lose
another 12 pounds you will have to reduce your calories
by yet another 250 calories per day to keep losing
Now you understand what causes the dreaded weight loss
But, it just gets worse.
Let’s say that you lose 12 or 24 pounds (corresponding
to 5-10 pounds of muscle or 250 to 500 calories per
day) and go off of your diet because you got
discouraged by the plateau.
When you regain your weight it comes back mostly as
fat, not as muscle. So now you need to eat 250-500
calories a day less just to maintain your weight.
The result is that you usually gain back more weight
than you lost.
Now you understand the cause of the dreaded weight loss
You can reduce the loss of muscle mass when you are
losing weight by adding the exercise component –
particularly resistance training.
But exercise can’t do it all. What you eat is important
as well. This is where leucine comes in.
“What is leucine?”, you might ask.
Leucine is an essential amino acid. It’s also what we
call a “branched chain” amino acid, a term that refers
to its chemical structure.
Leucine has been used by bodybuilders for years to
increase muscle mass when they are working out.
And there is good evidence that it is effective for
that purpose. I did a quick literature search and found
over 20 clinical studies on the topic in just the last
few years – but that is another story for another time.
It has just been in the last few years that evidence
started to accumulate that leucine can also help
preserve muscle mass when people are losing weight.
This research was spearheaded by Dr. D.K. Layman and
colleagues at the University of Illinois.
Their early studies showed that leucine stimulates the
synthesis of new protein in the muscle, suppresses
appetite and results in better blood sugar control. They
then showed that leucine supplementation during weight
loss in animals resulted in greater overall weight loss
and better retention of lean muscle mass.
They went on to do two clinical studies with women,
aged 40-56, who had BMIs of 31 (If BMI is not a
familiar term, suffice it to say that those women
really needed to lose weight).
Dr. Layman had discovered in preliminary studies
that leucine was most effective in preserving muscle
mass when the carbohydrate to protein ratio was 1.5:1
(For comparison, current dietary guidelines recommend a
carbohydrate to protein ration of 3.5:1, and that is
the formula most weight loss diets follow).
Thus, the experimental diet designed by Dr. Layman
provided 10 g of leucine/day in a diet with an overall
carbohydrate to protein ratio of 1.5:1. The control
diet only provided 5 g of leucine in a diet with an
overall carbohydrate to protein ratio of 3.5:1.
The two diets were identical in terms of calories
(~1700 calories/day) and were designed to create an
energy deficit of ~500 calories/day. The diets
contained identical amounts of fat (30% of calories)
and fiber (~20 g/day).
The first study lasted for 10 weeks and did not have an
exercise component. The second study lasted for 16
weeks and both groups in that study exercised 5
days/week using an exercise program designed to create
an energy deficit of 300 calories/day.
There was no significant difference in overall weight
loss between the high leucine – high protein
group and the control group in either study – but there
was a huge difference in where that weight loss came
In the study with the exercise component only 4% of the
weight loss came from muscle in the high leucine – high
protein group compared to 16% from muscle in the
As you might expect, the group that didn’t exercise
didn’t do as well. In that study 11% of the weight loss
came from muscle in the high leucine – high protein
group compared to 18% from muscle in the control group.
You may have noticed that exercise had only a modest
effect on preserving muscle mass for the subjects on a
standard weight loss diet (16% loss of muscle mass
with exercise compared to 18% muscle loss without).
The bottom line is that if you want to rely on exercise
to preserve muscle mass on a standard weight loss diet,
it really has to be high intensity, resistance
In contrast exercise was much more effective in
preserving muscle mass in the high leucine – high
protein group (4% loss of muscle mass with exercise
compared to 11% loss of muscle mass without exercise).
The bottom line is that weight loss diets providing
around 10 g of leucine/day coupled with a 1.5:1 ratio
of carbohydrate to protein are more effective at
preserving muscle mass than the kind of weight loss
diet that most people follow.
Some of you may be asking how this relates to Shaklee’s
Cinch Inch Loss Plan.
So it shouldn’t come as any surprise that in Shaklee’s
12 week clinical study of people on the Cinch Inch Loss
Plan the average weight loss was 15.4 pounds – and none
of that came from muscle!
Layman, J. Nutr, 133: 216S-267S, 2003.
Layman and Walker, J. Nutr., 133: 405-410, 2003
Layman et al, J. Nutr., 133: 411-417, 2003
Layman and Walker, J. Nutr., 136: 319S-323S, 2006
Jitomer and Willoughby, J. Med. Food, 11: 606-609, 2008
The Cinch Inch Loss Plan is a diet plan based on the
latest scientific advances in the field and clinical
studies show that it works!
To Your Health!
Dr. Stephen G Chaney