Re: fat loss in girls and women

[Guest guest]

----- Original Message -----

> I have recently come across some information that is somewhat contradictory

> from what is commonly believed. [...]

> In another study, a higher level of physical activity was related to a lower

> percent of body fat in males, however, in females, there was no relationship

> between physical activity and body composition. (Int J Obes Relat Metab

> Disord. 1997 Mar;21(3):184-8)

>

> Does anyone have any information on this topic? If these findings are

> accurate, it means that physical activity will not be beneficial to women

> for losing weight.

Dr. Yessis,

I am not sure I share your interpretation of the study. We do know that women's

bodies gain and store fat much more efficiently than men's, and that fat levels

are correlated with reproductive success.

Yet I would not conclude from this that physical activity will not be

beneficial. Activity can assist in creating the caloric deficit necessary for

fat loss. Other studies do seem to indicate that it plays a role, e.g.

Obes Res. 2004 May;12(5):789-98.

Exercise-induced reduction in obesity and insulin resistance in women: a

randomized controlled trial.

Ross R, Janssen I, Dawson J, Kungl AM, Kuk JL, Wong SL, Nguyen-Duy TB, Lee S,

Kilpatrick K, Hudson R.

" Daily exercise without caloric restriction was associated with substantial

reductions in total fat, abdominal fat, visceral fat, and insulin resistance in

women. Exercise without weight loss was also associated with a substantial

reduction in total and abdominal obesity. "

JAMA. 2003 Jan 15;289(3):323-30.

Effect of exercise on total and intra-abdominal body fat in postmenopausal

women: a randomized controlled trial.

Irwin ML, Yasui Y, Ulrich CM, Bowen D, Rudolph RE, Schwartz RS, Yukawa M, Aiello

E, Potter JD, McTiernan A.

" Regular exercise such as brisk walking results in reduced body weight and body

fat among overweight and obese postmenopausal women. "

Numerous other studies looking at obesity in large populations usually conclude

that physical activity is negatively correlated with obesity in both men and

women. For example, studies on the Amish men and women show that while both

genders put down an amazingly high amount of daily calories, including stuff

like bacon and butter, their high levels of physical activity keep them

relatively lean and free of cardiovascular disease.

I recall seeing a tidbit in the paper last week that suggested that for every km

that men and women walked as part of daily life, they reduced their chance of

being obese by 5%. Can't cite it though, unfortunately.

What I would conclude, then, from the collected evidence is that activity is

only one piece of the puzzle, and that any strategy aimed at fat loss must be

multifactorial.

For instance, here is a study that combined factors:

Int J Obes Relat Metab Disord. 1999 Oct;23(10):1035-46.

Effects of sex on the change in visceral, subcutaneous adipose tissue and

skeletal muscle in response to weight loss.

Janssen I, Ross R.

OBJECTIVE: To examine the influence of sex on whole body and regional

subcutaneous, visceral, total adipose tissue (AT), skeletal muscle (SM), and

lean tissue in response to weight loss induced by diet alone (DO) or the

combination of diet and aerobic (DA) or resistance exercise (DR)... CONCLUSIONS:

These findings indicate that in response to diet or diet and exercise-induced

weight loss, reductions in total adiposity, subcutaneous and visceral adipose

tissue distribution are not different in obese men and women. Independent of

sex, the combination of diet and exercise results in a preservation of skeletal

muscle mass, a preferential reduction of abdominal subcutaneous AT, and improved

functional capacity by comparison to diet alone.

-----------

I would be most interested in knowing what *type* of physical activity was

involved in the studies. I get a lot of email from women who tell me that the

standard prescription of low intensity cardio didn't make a difference to their

fat loss, but adding weight training did. I know from my own experience that an

hour of low intensity cardio a day made little difference in my bodyfat levels,

and it was not until I combined weight training, more intense cardio, and

attention to diet that I began noticing a difference.

Krista -Dixon

Toronto, Canada

kristasd@...

www.stumptuous.com/weights.html

[Guest guest]

Although we know through research and practice that exercise can be an

effective weight loss tool in men and women, women in general are not as

responsive to exercise-induced weight loss. This paradox is the result of

preferential distribution of fat stores and how these stores are

manipulated by the proteins expressed therein. In brief, fat storage is

mediated by lipoprotein lipase (LPL), while exercise induced fat metabolism

is regulated by hormone sensitive lipase (HSL) which is in turn activated

by adrenergic receptors. Essentially the cascades look like this:

insulin --> LPL --> lipogenesis

adrenergic agonists --> HSL --> lipolysis

Now not all adrenergic receptors are created equal when it comes to fat

loss. The beta receptors work quite well, while the alpha receptors do not

work well at all. Now lets look at the distribution of these enzymes and

receptors in the male and female body:

Men

abdomen - high HSL, high LPL, high beta receptors

periphery (ie. bum, hips, legs) - low HSL, low LPL, low beta receptors

Women

abdomen - high HSL, low LPL, high beta receptors

periphery - low HSL, high LPL, low beta receptors

What does this all mean? 1/ Men store fat better in the abdominal region,

women in the hips, 2/ adrenergic output during exercise enhances lipolysis

in the abdomen in men and women, however women don't store much there so

men respond better to exercise, 3/ women have a real difficult time

shedding those extra pounds off the hips because that is where preferential

storage occurs, yet it is not a preferential site for adrenergic

action. So basically women get the shaft when it comes to fat loss. They

have to work much harder then men (in general) to experience the same

gains. Another reason men should be thankful for not having the burden of

child bearing.

Trevor Cottrell

Kingston, ON

CANADA

[Guest guest]

This reply is more of an opinion based on years of observation and

body-composition testing.

I liked one of the studies Krista -Dixon posted in her reply:

Obes Res. 2004 May;12(5):789-98.

Exercise-induced reduction in obesity and insulin resistance in

women: a randomized controlled trial. Ross R, Janssen I, Dawson J,

Kungl AM, Kuk JL, Wong SL, Nguyen-Duy TB, Lee S,

Kilpatrick K, Hudson R.

" Daily exercise without caloric restriction was associated with

substantial reductions in total fat, abdominal fat, visceral fat,

and insulin resistance in women. Exercise without weight loss was

also associated with a substantial reduction in total and abdominal

obesity. "

I would like to emphasize the " Daily exercise without calorie

restriction. " I my years of observation, I have found in women a

correlation between frequent exercisers and an abundance of lower-

body subcutaneous fat. It seems the more a woman exercises and

controls her diet (read insufficient calorie intake), the harder

this lower body fat resists exercise. It is my opinion that

reducing calories invokes an emergency burn muscle/store fat biased

metabolism.

Further emphasis on more exercise and/or fewer calories to get rid

of this " stubborn fat " only leads to more stubborn fat. Those

successful at reducing this fat in this way are usually prone to

rebound fat gain. In observing women that compete, I am amazed at

the fast, but large weight fluctuations that these women endure.

The part about " Exercise without weight loss was also associated

with a substantial reduction in total and abdominal obesity, "

suggests that an increase in muscle tissue was achieved. This is

the opposite of burn muscle/store fat.

This concurs with my outlook on exercise and weight-loss for women,

as well as men. And that is that exercise without caloric

restriction will result in fat-loss and muscle gain. I will not buy

into the 'eat less calories than you consume' mentality. It is my

belief that if you eat what your body requires, and exercise, the

body will rid itself of excess fodyfat, and will allow muscle to be

built in response to the additional physical activity.

I'm not including exercise variables here, because some workouts

are better than others. But the fact remains that women have been

given the wrong information about weight control for over 40 years.

And they are fatter.

Wayne Montierth

Sandy, Utah

[Guest guest]

Well, I'm 1 case in which physical exercise clearly lead to fat loss and

muscle gain. I was 36 when I started training.

What I did was simple - I trained powerlifting exercises, 3 days only a

week, and did no cardio. I also did not change my eating at all. This

means including whole pints of ben and jerry's in my eating. I.E. a true

see food diet.

I would say that the results had to be clearly from gaining muscle mass and

losing bodyfat, as my waist went from an original 39 " to 32 " . I went from a

heavyweight to 198 division.

I gained strength - and size in areas - and lost the fat on my waist quite

dramatically.

However, I would like to bring up that the BMI is a lousy standard to

measure by - without the " under 35 " waist exception that has been published,

I'd be " obese " by the darned BMI. That's how bad a standard that thing

REALLY is.

So my BMI comes up just a shade over 30 still, despite my obvious NON obese

status.

I found that success for me was based on NON restriction of my diet, and

lifting heavy 3 days a week. Perhaps people are trying too hard, doing too

much AND under caloried? Perhaps they should not do MORE workouts, but more

intense ones and fewer of them?

The Phantom

aka Schaefer, CMT, CSCS, competing powerlifter

Denver, Colorado, USA

Dr. Yessis has written:

> Some of the doctors that I work with say that in their practice, helping

> women to lose weight, they find that many women do not experience fat loss

> (even though they may lose some weight) when they exercise. They believe it

> is a defense mechanism unique to women .i.e., when the body is stressed, as

> in physical activity, the body goes into a fat-saving mode for preservation.

> However, when a woman is at the weight that she should be, it then appears

> that exercise is extremely beneficial in not allowing any fat gain.

>

> The key point here is knowing whether physical exercise , by itself, will

> lead to fat loss in overweight women. For example, even in my practice, I

> know of quite a few women, including athletes, who can't seem to lose any

> fat, no matter how hard they exercise. Calorie-restriction diets alone

> appear to be more effective. However, when coupled with exercise, the fat

> losses seem to stop or slow down greatly.

[Guest guest]

Dr. Yessis

Could fat loss in women be related to different endocrine system in women and

men? Both have different cycles, wich I don't know very precisely. One

question come to my mind : What is the age of the women you are

relating to? It is known that women in their menopausal period have

usualy more trouble losing bodyfat than when they were young. Do you

think it could influence the final result?

That said, I recently met a person telling me about the benefit of

coconut oil (CO) for fat loss and thyroid function and that she

experienced serious fat loss after she introduced CO to her diet. I'm

reluctant to claim any food a panacea but I'm always curious to know

more, as there is often misleading information about nutrition.

So, I am making some research about all this and so far, it seems

that there is a link between medium-chain fats (MCF), metabolism and

thyroid function. I have yet to know exactly all of the functioning.

Does anybody have more info about MCF and metabolism?

Laforest

Chambly, Québec, Canada