Yo yo dieting is bad

[Guest guest]

Hi All,

I pasted below something from the brother group that you might be

interested in re yo yo diets.

Cheers, Al.

PDF available, All,

It seems to me they lost and gained

weight too quickly. CR weight changes

(negative) are best done slowly maybe.

Cheers, Al.

Metabolism 2002 Feb;51(2):149-54

Effects of intentional weight cycling on

non-obese young women.

Kajioka T, Tsuzuku S, Shimokata H,

Sato Y.

This study investigated the effects of intentional

weight cycling in non-obese,

young women (n = 5; mean age, 24.6 years; mean body

mass index [bMI], 20.5

kg/m(2)). During the first 30 days, the subjects lost

more than 4 kg with energy

restriction alone (first diet period). In the

following 14 days, they regained

more than the weight they had lost by eating ad

libitum (free-living period). In

the subsequent 30 days, they once again lost more than

4 kg with only energy

restriction (second diet period). Height, weight,

waist and hip circumferences,

body composition, lipid profiles, thyroid hormones,

systolic and diastolic blood

pressures (SBP, DBP), and resting energy expenditure

(REE) were examined.

Measurements were taken at the beginning of the study

(day 0), at the end of

each diet period (day 30 and day 74), the end of the

free-living period (day

44), and on day 180. The mean change in each variable

from baseline (day 0) was

used and controlled for the baseline value, baseline

weight, and change in

weight (Delta weight). Statistical tests were

performed to determine the

significance of the mean changes in the variables. By

day 180, there were

significant decreases in the subjects' lean body mass

(P <.01), serum

triiodothyronine (T(3)) (P <.001), serum total

thyroxine (T(4)) (P <.001), and

REE (P <.001), and significant elevations of SBP (P

<.05) and DBP (P <.001). The

lipid profiles had not changed except for increased

triglycerides (TG). These

results suggest that weight cycling through energy

restriction alone may have

negative health consequences in non-obese, young

women. Copyright 2002 by W.B.

Saunders Company

PMID: 11833040 [PubMed - indexed for MEDLINE]

ALL:

Your article Al, points out

an important issue that

is useful to remember.

Anybody who restricts

calories must stay

permanently

restricted, or they will

tend to add mostly fat,

if they suddenly eat a lot.

In order to survive in tough times, all organisms

which are starved and without food:

1) lower metabolism to save energy

2) decrease muscle tissue to save energy

3) increase body fat whenever possible, to store

energy

The increased body fat helps the animal to survive

longer,

and to survive more easily, in preparation for the

next period of starvation when it arrives.

So whoever goes off his diet and eats a lot --

that person can be sure his food is going to

show up as extra body fat!

-- Warren