I've taken the Tonalin CLA.  Like you, I noticed increased muscle mass.  At
the time I began taking it, I was working out with weights on a daily basis
and was able to increase the amount of weight used rather quickly.  Then I
became ill for some time and wasn't able to work out at all.  Amazingly, no
muscle mass was lost at all!

I continued to take the CLA until I read a report about it possibly raising
blood sugar in diabetics.  I'm diabetic.  I did some more research and
decided to stop taking it.  Muscle mass slowly began to decrease.  I didn't
notice any difference in my blood sugar.  I decided to take it again.  This
time, I was slacking off on my workouts because again, I had been sick.
This time, I was sick off and on but hadn't regained enough strength to feel
like working out.  I've regained the muscle mass.  Weird!

Hopefully I'll be able to resume my workouts once this current sinus
infection clears.  I'm feeling better, but don't want to push it.  Will see
how things go from there.  I know when I resumed my workouts in the past, I
didn't have to start out with lower weights as I had to prior to taking the
CLA.

I decided to take CLA given the study that showed reduced cancer risk.  I
never expected more from it.  I am losing weight, but I was losing weight
before too.

This 1-yr human study showed that CLA increased lean muscle mass.  But
it also raised A1C, lowered HDL and raised LDL.

Choose your poison.

 Hat tip to tintinet in misc.fitness.health who first posted the link.
If you're interested more in this, I suggest searching in
google-groups in misc.health.fitness on CLA.  There's several good
threads with arguments pro and con.

Adam Becker
----------------------------

http://www.ajcn.org/cgi/content/abstract/79/6/1118

Conjugated linoleic acid supplementation for 1 y reduces body fat mass
in healthy overweight humans1,2,3
Jean-Michel Gaullier, Johan Halse, Kjetil Høye, Knut Kristiansen, Hans
Fagertun, Hogne Vik and Ola Gudmundsen

1 From the Scandinavian Clinical Research AS (JMG, KK, and OG) and the
Scandinavian Statistical Services AS (HF), Kjeller, Norway; the
Betanien Medical Center, Oslo (JH); the Helsetorget Medical Center,
Elverum, Norway (KH); and the Matforsk (Norwegian Food Research
Institute), Ås, Norway (HV).

Background: Short-term trials showed that conjugated linoleic acid
(CLA) may reduce body fat mass (BFM) and increase lean body mass (LBM),
but the long-term effect of CLA was not examined.

Objective: The objective of the study was to ascertain the 1-y effect
of CLA on body composition and safety in healthy overweight adults
consuming an ad libitum diet.

Design: Male and female volunteers (n = 180) with body mass indexes (in
kg/m2) of 25-30 were included in a double-blind, placebo-controlled
study. Subjects were randomly assigned to 3 groups: CLA-free fatty acid
(FFA), CLA-triacylglycerol, or placebo (olive oil). Change in BFM, as
measured by dual-energy X-ray absorptiometry, was the primary outcome.
Secondary outcomes included the effects of CLA on LBM, adverse events,
and safety variables.

Results: Mean (± SD) BFM in the CLA-triacylglycerol and CLA-FFA groups
was 8.7 ± 9.1% and 6.9 ± 9.1%, respectively, lower than that in the
placebo group (P < 0.001). Subjects receiving CLA-FFA had 1.8 ± 4.3%
greater LBM than did subjects receiving placebo (P = 0.002). These
changes were not associated with diet or exercise. LDL increased in the
CLA-FFA group (P = 0.008), HDL decreased in the CLA-triacylglycerol
group (P = 0.003), and lipoprotein(a) increased in both CLA groups (P <
0.001) compared with month 0. Fasting blood glucose concentrations
remained unchanged in all 3 groups. Glycated hemoglobin rose in all
groups from month 0 concentrations, but there was no significant
difference between groups. Adverse events did not differ significantly
between groups.

Conclusion: Long-term supplementation with CLA-FFA or
CLA-triacylglycerol reduces BFM in healthy overweight adults.

Key Words: Conjugated linoleic acid · body fat mass · lean body
mass · weight · body mass index · dual-energy X-ray
absorptiometry · overweight · humans