studied the effectiveness of a structured internet
behavioral weight loss program (VTrim) compared
to a commercial internet weight loss program (eDiets.-
com). The results found the structured behavioral
weight loss program, led by a therapist, to be signifi-
cantly more effective than the self-led commercial
weight loss program. VTrim participants lost twice
as much weight throughout the study and were nearly
twice as likely to have kept it off after twelve months.
While the internet is a practical medium for commer-
cial weight loss programs, their impact would be more
noticeable if they integrated more structure such as
that used in VTrim.
Another study at the University of Vermont
involved participants using an internet based behav-
ioral weight loss program for one year. All partici-
pants used the same program, but half supplemented
with face-to-face meetings once a month. The study
concluded that participants lost approximately the
same amount of weight whether or not they attended
meetings in person.
The University of Pennsylvania School of Medi-
cine began a year long controlled study in 2001 com-
paring eDiets.com to a weight loss manual to gage
overall effectiveness for modifying an individuals life-
style. Forty-seven female participants followed either
eDiets.com or the LEARN Program for Weight Con-
trol. This small study concluded the manual had a
greater impact on weight loss than eDiets since
women following the manual lost approximately four
percent of their body weight as compared to only one
percent loss in women who used eDiets.com.
Research on the effectiveness of online diet pro-
grams remains limited. Studies at major universities
demonstrate that websites such as eDiets.com can be
effective tools for weight loss, but are usually most
successful when coupled with personalized feedback.Resources
PERIODICALS
‘‘E-Diets.’’Health Magazine. (February 2005). Also avail-
able online at<http://www.health.com/health/web/
DietGuide/ediets.html>.
Gold, Beth, et al. ‘‘Weight Loss on the Web: A Pilot Study
Comparing a Structured Behavioral Intervention to a
Commercial Program.’’Obesity. 15(2007): 155-164.
Hansen, Matthew. ‘‘Print Works Better than Web for
Weight Loss, Research Suggests.’’DOC News.
1(2004): 19.
Micco, N., et al. ‘‘Minimal In-person Support as an Adjunct
to Internet Obesity Treatment.’’Annals of Behavioral
Medicine. 33(February 2007): 49-56.
Womble, Leslie G., et al. ‘‘A Randomized Controlled Trial
of a Commercial Internet Weight Loss Program.’’
Obesity Research. 12(2004): 1011-1018.
ORGANIZATIONS
Callahan, Maureen. ‘‘eDiets.com Diet Checklist from
Health Magazine.’’AOL diet & fitness. (October 2004).
<http://diets.aol.com>.
eDiets.<http://www.ediets.com>.
‘‘eDiets.com.’’TopTenReviews. (2007).<http://online-diet-
services-review.toptenreviews.com/ediets-com-
review.html>.Stacey L. ChamberlinElectrolytes
Definition
Electrolytes are ions that form when salts dissolve
inwateror fluids. These ions have an electric charge.
Positively charged ions are called cations. Negatively
charged ions are called anions. Electrolytes are not
evenly distributed within the body, and their uneven
distribution allows many important metabolic reac-
tions to occur.Sodium(Na+), Potassium (K+),Cal-
cium(Ca2+),Magnesium(Mg2+), chloride (Cl-),
phosphate (HPO 4 2-), bicarbonate (HCO 3 -), and Sul-
fate (SO 4 -) are important electrolytes in humans.Purpose
Electrolytes play a critical role in almost every
metabolic reaction in the body. For example, they:
Help control water balance and fluid distribution in
the body
Create an electrical gradient across cell membranes
that is necessary for muscle contraction and nerve
transmissionQUESTIONS TO ASK YOUR
DOCTOR What is an ideal target weight or body mass
index?
Which meal plan best accommodates special
diets or dietary restrictions?
What type of exercise should be avoided?
How often should follow-up care be scheduled?Electrolytes