This research was funded, in part, by a grant from the
National Institute of Diabetes, Digestive, and Kidney
Diseases (R43 DK42397). Please do not quote without
permission.
Objectives
Objective # 1.
Test and
refine components of the paper and pencil version through
research with overweight subjects.
We recruited subjects to test the program. The purpose of
this aspect of the research was fourfold: 1) to obtain
initial data on the appropriateness of the caloric
adjustment and exercise algorithms; 2) to obtain data on
palatability and ease of preparation of menus; 3) to obtain
feedback on the initial drafts of the supplementary manuals;
and 4) to obtain feedback on a wide range of design and
development issues in a focus group format.
This research continued for several months and over 50
subjects participated. During this period, the program was
under constant development and the opinions and data
provided by subjects resulted in extensive revisions to
program algorithms, menus, and written materials.
Objective # 2.
Assemble an Initial Computer Prototype Using Information
Gained with the Paper and Pencil Research.
Based on refinements to the program made during the paper
and pencil trials, an initial computer prototype (Beta-I)
was assembled and a second version of support materials
drafted. One indication of the impact of the paper and
pencil research on program development is that we decided to
completely revise the program menus on the basis of feedback
from users suggesting that the food combinations, although
meeting strict nutritional criteria, were not very
palatable. This is one example of how both scientific
(nutritional) information and consumer feedback guided
program development.
Objective # 3.
Assess Usability and
Reliability of the Prototype with a Small Group of Subjects.
In preparation for a self-help trial, we recruited 10
subjects who had completed the paper and pencil trials to
serve as initial test subjects for the computer prototypes.
Subjects used the computers for varying periods of time
ranging from a few weeks to several months. Subjects met
every two weeks with a research assistant to upload data
from the computer and to discuss their experiences and
opinions related to treatment.
From this research we were able to ascertain that the
program was easy to follow and the reliability of the units
was acceptable. We also gained important information related
to specific program components and made many program
modifications as a result.
Subjects
Subjects were 24 women 2 men recruited through newspaper
advertisements for a weight loss research trial. Mean age of
subjects was 41.1 years (SD = 7.3) and mean number of years
of education was 15.1 years (SD = 1.9). All subjects had
previous dieting experience with 56% reporting having been
on 10 or more diets in the past. At pretreatment assessment,
subjects were a mean of 21% over ideal weight (based on
guidelines provided by U.S. Department of Agriculture and
U.S. Department of Health and Human Services, 1990).
Procedures
Prior to treatment, a 45-minute assessment
was conducted to explain the program, obtain informed
consent, collect demographic data, physical measures, and
ratings of confidence and body satisfaction. Subjects
received their computers, instructions for use, and
supporting manuals in small groups of 8 - 12 and were asked
to begin treatment. Treatment was run in a self-help manner
without further group meetings or therapist-assistance. At
treatment end, subjects were assessed on the same measures
collected prior to treatment and they were administered a
detailed structured interview that explored their
impressions of the program and ideas for modifications and
improvements.
Treatment
The computer worked by tailoring a nutritionally balanced
meal plan for each individual user at a caloric level
appropriate to allow for weight loss of .5 - 1.5 lbs.
weekly. Subjects entered their weight daily and caloric
levels were adjusted periodically if weight loss was too
rapid or too slow. Users selected from among 75 meals, and
the computer provided nutritionally equivalent substitution
lists for foods and allowed users to change quantities of
individual food items.
Individualized exercise targets were provided for a wide
range of activities. Following a one-week baseline where
subjects recorded their usual exercise, the computer
provided exercise targets that gradually increased up to an
equivalent of 300 calories expended for each of three weekly
exercise sessions. The computer prompted users for
mealtimes, drinking water, and exercising, and also provided
a daily summary screen showing progress toward meeting daily
target goals for total calories, percent calories from fat,
and calories expended exercising.
Variables
Four sets of variables were collected during this study
including: demographic and historical variables; physical
measures such as weight, body mass index (BMI),
circumference measures, blood pressure, and body fat,
ratings of program ease of use and program satisfaction and
confidence in success; and a structured interview at
treatment end to gather opinions concerning program
modifications.
Results
Results are presented for 18 subjects who completed 12
weeks of treatment. For weight and BMI t-tests revealed
significant change from pretreatment to posttreatment, t(17)
= 6.38, p<.0001; and t(17) = 6.30, p <.0001, respectively
(see Table 1 below).
