Dietmate - Computerized Self-Management for Weight Control

Computerized Self-Management for Weight Control

Albert Jerome & Lee W. Frederiksen
Health Innovations, Inc., Reston, VA

Rapid progress in computer technology has facilitated the development of small, fully-dedicated hand-held computers that are powerful and relatively inexpensive. Health Innovations, Inc. (HII) specializes in applying this technology to the development of behavioral self-management programs. HII developed the LifeSign Program for smoking cessation. LifeSign is a tiny computer that implements a gradual withdrawal program based on basic behavioral principles (Klepac, 1990; Prue, Riley, Oriandi & Jerome, 1990). More recently, HII developed a computerized self-management program for weight control: DietMate.

The DietMate Program

DietMate was developed with the goal of providing a scientifically valid self-management program that would meet consumer demand for an effective, cost-efficient, readily disseminable approach to weight control. By combining the most effective components of behavioral weight loss programs with microcomputer technology, DietMate represents a novel approach to weight control that provides advantages over many traditional clinic-based and self-help treatments.

The heart of the DietMate Program is a fully-dedicated microcomputer that implements a weight control intervention incorporating sound nutrition, exercise, and principles of behavior modification. DietMate greatly simplifies the task of self-monitoring, and it structures-through a series of prompts and feedback messages-eating and exercise choices without the need for extensive knowledge on the part of users. Moreover, treatment is applied interactively in the user's natural environment. Treatment parameters are adjusted dynamically in response to user behavior, feedback is provided instantaneously, and self-monitored data is stored and manipulated in sophisticated ways, such as the display of long-term progress charts.

Hardware. The computer developed by HII for this application (see Figure 1) measures approximately 6 1/2" by 3 3/4" thick (with cover closed), weighs just over 1 lb., and operates on 4 AA batteries. The computer has seven operating buttons plus an on/off button and volume control, and is encased in a hard plastic shell with a cover that folds back to become a stand. The LCD display measures 3 3/4" by 1 7/8" and has two sections. The bottom section of the LCD is not matrix type and can display graphics or text (8 lines by 32 characters per line). The top section of the LCD has 4 icons for prompting meals, exercise, weighing, and drinking water and displays for volume setting, date, and time. The computer has an 8-bit 8OC88 microprocessor with 256 kilobytes ROM and 32 kilobytes RAM and a 4-bit 75304 microcontroller.

In addition to the computer, the DietMate Program includes a startup guide; a program manual that details computer functions and provides background information on important topics in weight loss such as nutrition, exercise, and maintenance; a gourmet cookbook; and an instructional video.

How DietMate Works.

DietMate is highly prescriptive and interactive. Behavioral principles such as goal setting, self-monitoring, stimulus control, feedback, and shaping are integrated at all levels of the program to foster changes in eating and exercise habits and to maximize user compliance.

When users first start the program, the computer provides a tutorial of key functions and then prompts them to enter height, weight, age, sex, activity level, weight loss goals, usual mealtimes, and preferred exercises.

On the basis of this information, a set of menus is individualized to a caloric level that projects gradual, steady weight loss. The menus are nutritionally balanced, meeting the recommendations of the Dietary Guidelines for Americans, 1990 (U.S. Department of Agriculture & U.S. Department of Health and Human Services, 1990), as well as those of nine other major health organizations that publish nutritional guidelines.

Users input their weight daily and the computer makes periodic changes to the menus to adjust calories up or down as needed to regulate weight loss within a safe range (approximately .5 to 1.5 lbs. weekly) and, following attainment of desired weight, to maintain weight. DietMate also responds to user input on a meal-by-meal basis. For example, if overeating or undereating occurs at breakfast or lunch, subsequent meals are adjusted to keep total caloric intake in line with prescribed daily target.

DietMate uses visual (icons and text) and auditory prompts to remind users to eat, exercise, and drink water, thereby encouraging the development of stimulus control over these behaviors. In response to cues, users pick the appropriate action by highlighting an item from a list of actions and pressing a button. DietMate then provides a series of screens that allows them to make appropriate selections and record their behaviors. For example, at lunch time the "eat" icon is lit and the message: "Its time for lunch" is on the screen. Users select "Lunch" from a list of actions and press a button. The next screen displays three major categories of meals: "Home," "Restaurant," and "Planned Meal," from which users select their choice. Within the "Home" meal category, they can select "Quick & Easy" meals, which can be prepared in 20 minutes or less; "From the Cookbook" meals, which are more elaborate and prepared with reference to cookbook instructions; or "Frozen Foods," which includes a variety of frozen entrees. Selecting "Restaurant" results in a display of nine popular restaurant types, with various meal selections available within each category. "Planned Meal" is used to display meals that were scheduled previously by the user. Any meal selected from the various categories will be nutritionally balanced and at the appropriate caloric level for the user.

Following selection of a meal, the caloric content and percent calories from fat are displayed, and users are provided with the option of recording their meal or first changing item quantities or modifying the menu by substituting for specific items with nutritionally equivalent foods.

The exercise prescription begins with a one-week baseline of the user's typical exercise pattern. Subsequently, users are prompted when to exercise and are provided with exercise targets-the number of minutes they should exercise-for a wide range of activities. Users select their desired exercise, record their behavior, and receive feedback from the computer. As the program progresses, they are shaped to gradually increase caloric expenditure. The exercise prescription follows the guidelines provided by the American College of Sports Medicine (1990).

The program has an extensive feedback system that provides messages at several different times: immediately following behavior, as a summary at the end of the day, as a reminder or "to do" list in the morning, and as a summary at the end of each week. The feedback system tracks important variables such as total caloric intake, percent calories from fat, number of exercise sessions, and total calories expended exercising, and categorizes the history of these variables into discreet patterns. For example, the first missed exercise session following compliance with exercise would be classified as a "slip." Similarly, a variety of other patterns are defined on the basis of the frequency and timing of behaviors. Thus identified, these patterns result in the display of feedback messages that vary in frequency, phrasing, and tone. The feedback system also incorporates principles of fading by adjusting the schedule on which messages are delivered. For example, a newly acquired behavior may be followed by positive feedback on a continuous reinforcement schedule. As it is consistently performed, the feedback becomes less frequent (variable ratio schedule). If the person slips, the frequency of feedback is again increased.

An additional source of daily feedback is provided by a summary screen-accessible at any time-that documents progress toward meeting daily goals for caloric intake, percent of calories from fat, and exercise. Longer-term feedback is provided by a weekly summary and by charts and graphs that show history of weight loss, calories expended exercising, and caloric intake.

One of the primary components of DietMate is a fully-integrated maintenance phase. Following attainment of goal weight, the program continues to prompt users to enter their weight and continues to monitor and structure food intake and exercise. If significant weight gain is detected, users are automatically put back into a weight loss phase as appropriate. Given the critical importance and difficulty of maintaining weight loss following behavioral treatment (e.g., Brownell & Wadden, 1986; Foreyt, 1987), the ability to continue monitoring eating and exercise behavior and to implement program changes in response to significant changes may be one of the important advantages of computerized treatment over traditional treatment delivery systems.

DietMate also includes several other features designed to enhance usability and user compliance. For example, in conjunction with the meal planning feature, which allows daily meals to be planned for up to 14 days, a shopping list can be generated that includes all items needed to prepare the planned meals. DietMate also has a calorie and exchange option that allows users to record foods eaten by entering their caloric values or by using the exchange system developed by the American Diabetes Association and the American Dietetic Association and adopted by several popular weight loss programs.

DietMate as a Research Tool

DietMate not only provides a vehicle for implementing a weight loss and maintenance program, it also functions as a self-monitoring device that accurately records and stores important treatment variables such as weight, number of meals eaten, frequency of snacking, total caloric intake, percent calories from fat, and number of exercise sessions and calories expended exercising for up to two years. An internal serial port allows for uploading these data to a desktop computer for analysis. These features make DietMate a useful research tool that may facilitate study of the interrelationships among process variables during weight loss treatment.

As a further refinement, customized software can be used to implement treatment protocols of interest to experimenters. By taking advantage of the precise codification and standardization of treatment parameters that are possible with hand-held computers, outcome studies can be run using sets of computers that execute closely matched protocols that differ only in ways specified by researchers. These computers can serve both to implement the treatment protocols and to collect and store data that reflect subject behavior and treatment adjustments in response to that behavior as they occur across time in the subject's natural environment.


DietMate is a computerized self-management program for weight control that combines the characteristics of effective clinic-based behavioral care with the advantages of interactive treatment in the user's natural environment. It includes features such as real-time prompting of behavior, simplified self-monitoring, instantaneous feedback, adjustment of treatment parameters in response to user behavior, and automated data collection and storage that are not available with more traditional program delivery systems. Precise codification of treatment parameters, coupled with the data collection and storage features, make it a useful instrument for weight loss research. As such, DietMate represents important progress in the use of computer technology for developing clinical and research tools in the behavioral sciences. Moreover, as a sophisticated self-management program in a delivery system that can be disseminated readily to a wide consumer audience, it has the potential to produce a significant public health impact.

  • American College of Sports Medicine. (1990). Position stand: The recommended quantity and quality of exercise for developing and maintaining cardiorespiratory and muscular fitness in healthy adults. Medicine and Science in Sports and Exercise, 22(2), 265-274.
  • Brownell, K. D., & Wadden, T. A. (1986). Behavior therapy for obesity: Modern approaches and better results. In K. D.

  • Brownell &J. P. Foreyt (Eds.), Handbook of eating disorders: Physiology, psychology, and treatment of obesity, anorexia, and bulimia (pp. 180-197). New York: Basic Books.

  • Foreyt, J. P. (1987). Issues in the assessment and treatment of obesity.Journal of Consulting and Clinical Psychology, 55, 667-684.

  • Klepac, R. K. (1990). LifeSign: A computer-based self-help smoking cessation program. The Behavior Therapist, 13(3), 67-68.

  • Prue, D. M., Riley, A. W., Orlandi, M. A., & Jerome, A. (1990).Development of a computer-assisted smoking cessation program: A preliminary report. Journal of Advancement in Medicine, 3(2), 1990.

  • U.S. Department of Agriculture & U.S. Department of Health and Human Services. (1990). Nutrition and your health: Dietary guidelines for Americans. Washington, DC: U.S. Government Printing Office.

The development of DietMate was funded, in part by grant #1R43 DK42397-OIA2 from the National Institute of Diabetes and Digestive and Kidney Diseases.

Review of DietMate

Art Freeman

I love food. I enjoy preparing it, serving it, and, of course, eating it. Of course, I pay a price for my gluttony. I have always been tempted to order those preparations advertised in the late night "Infomercials." You know the ones, "Eat all you want of whatever you want. This small pill taken before bedtime allows your body to burn off three pounds of fat per night." Would they lie to us? They even have satisfied customers with their before and after pictures. "John M. of Sheboygan, WI, lost three hundred pounds in the first year." I don't order them because I believe that anything that sounds too good to be true usually is.

I recently had the opportunity to try something new. The DietMate computer from Health Innovations of Reston, Virginia. The DietMate comes with a program guide, a start-up guide (for those of us who are chomping at the bit), a videotape of instructions, and a gourmet cookbook filled with tasty low-calorie recipes. Maybe this was what I have been waiting for all these years. After all, the thing I like second best to food is gadgetry.

First, I really liked the computer and the premises upon which it has been designed. It uses a behavioral approach to obtain baseline data and to then monitor and guide the program participant through the various stages of dieting. It is a small, compact and apparently very sophisticated machine. Getting started is quite simple. The computer takes you through all of the start-up steps with clear instructions. The LCD screen is easily read, there are several warning messages programmed into memory. If you enter the requested data during the day the DietMate will provide you with a daily summary each evening. At the end of the week, the DietMate provides a weekly summary that highlights your progress during the week. The summaries include the targets for the day, the actual consumption, and exercise calories.

A number of exercise evaluations are offered by DietMate, (e.g., stationary cycle, swimming, tennis [singles or doubles], or walking). You can also add or delete exercises.

The computer helps schedule your menus. The food list is quite extensive. (How do they get so much into so small a machine?) You have choices of eating at home (complete with recipes) or eating out in restaurants including American, Chinese, Fast Food, French, Greek, Italian, Japanese, Mexican, or Seafood. That just about covers it. The DietMate will tell you the calories in almost any food so that you can even take the DietMate with you to the market and use it as you shop.

The DietMate cookbook is filled with excellent recipes. I've tried several and found them to be quite tasty.

The only problem that I found with the DietMate was that it was not easily carried, and was not convenient. To follow the program, the Dietmate needs to be carried around all of the time. While it is small, it still requires putting it in a case. I found that if I left it at home for the day, or left it at the office, data may not have gotten entered. The issue is, of course, one of maintaining a high level of motivation. The computer is fun, interesting, and potentially valuable. If it were more easily carried (as with a belt loop), I would have been happier and possibly used it more often. As it was, I stopped carrying the DietMate after about three weeks. During that time I lost five pounds. More, I think, from the constant awareness that I had to carefully monitor my food intake. The Dietmate could not, unfortunately force me to exercise.

If you like gadgets and want to pay the price for one of the more interesting gadgets on the market, the DietMate may be helpful.


The initial DietMate validation study, funded with a Phase I SBIR grant from the National Institute of Diabetes and Digestive and Kidney Diseases, was conducted using early computer prototypes of the DietMate program. Twenty-six subjects who were a mean of 21% over ideal body weight participated in the 12-week trial. Among 18 subjects who completed the study, the results showed statistically significant reductions in body weight, body mass index, percent body fat, diastolic blood pressure, and bicep circumference. Eighty-three percent of subjects who completed the study experienced weight loss (M = .51 lbs. per week, SD = .32). At treatment end, 70% of subjects rated themselves as being either "very satisfied" or "extremely satisfied" with the program, and 63% of subjects rated the program as being either "very easy" or "extremely easy" to use.

The initial study using the commercial version of DietMate was a 12-week self-help trial conducted with 24 subjects (17 women and 7 men) who were a mean of 26% over ideal body weight. Among 21 subjects who completed the trial, results showed statistically significant reductions in weight (M = 10 lbs., SD = 6.7), body mass index, diastolic and systolic blood pressure, and resting pulse. Subjects also showed significant improvement in scores on a self-report body satisfaction scale. Subjects reported a high level of overall satisfaction with the program (M = 5.9, SD = 1.4 on a 1 - 7 scale) and rated the program as being very easy to use (M = 5.8, SD = 1.2 on a I - 7 scale). Results of this study were presented at the annual convention of the Society for the Advancement of Behavior Therapy, New York, NY, November, 1991.

A third study, funded by a Phase I SBIR grant from the National Heart, Lung, and Blood Institute (NHLBI), examined the effectiveness of DietMate for weight loss and cholesterol reduction among 34 subjects in a 12-week self-help trial. At pretreatment, subjects were a mean of 21% overweight and had mean total cholesterol levels of 250 (SD = 28) and low-density lipoprotein levels (LDL) of 170 (SD= 24). At treatment end, results showed statistically significant reductions in body weight, total cholesterol, low-density lipoprotein (LDL) levels, and resting pulse, as well as waist, chest, and bicep circumference. Subjects also reported significant increases in ratings of overall body satisfaction and significant decreases in Beck Depression Inventory scores. Overall, subjects reported high levels of satisfaction with the program (M = 5.4, SD = 1.2 on a 1 - 7 scale) and rated it as being easy to use (M = 5.6, SD = 1.1 on a 1 - 7 scale). Results of this study were presented at the annual convention of the Society of Behavioral Medicine, New York, NY, March, 1992. A fourth DietMate study, funded by a Phase I SBIR grant from NHLBI, is being conducted to examine the effectiveness of DietMate as exercise intervention among a sample of 30 subjects. Results of this study are not yet available.

Based on the results of the cholesterol reduction study, Phase II SBIR grant funding is being provided by NHLBI for further development and evaluation of a version of DietMate specifically for cholesterol reduction. This project, scheduled to begin in August, 1993, will include a randomized clinical outcome trial and long-term follow-up comparing the effectiveness of DietMate with a standard self-management intervention.


Development and evaluation of LifeSign was funded in part by two Phase I and one Phase 2 Small Business Innovation Research (SBIR) grants awarded to Health Innovations, Inc. (HII) by the National Institute on Drug Abuse, and one Phase I SBIR grant from the National Cancer Institute (NCI).

A Phase 2 SBIR grant from the NCI to complete development and study the long-term effectiveness of a LifeSign program for smokeless tobacco cessation is currently underway. This study includes a multi-site randomized clinical outcome trial comparing LifeSign with a self-help treatment manual developed for smokeless tobacco users.

The results of completed studies are presented as a series of papers described below:

The first LifeSign research paper entitled "Development of a Computer-Assisted Smoking Treatment Program: A Preliminary Report", was published by Harvard University's Institute for the Study of Smoking Behavior and Policy in February 1988. This paper presents the results of two clinical trials. The first study reported a one-year carbon monoxide (CO) validated abstinence rate of 18.5%, while the second reported a CO validated one-year abstinence rate of 22%. One study was conducted by HII; an independent research institution conducted the second study.

The second paper, which is a revised version of Harvard University's Discussion Paper, was published by the Journal of Advancement in Medicine (1990, volume 32, pp. 131-139). Portions of the research contained in this paper were presented at the Annual Scientific Sessions of the Society of Behavioral Medicine held in Washington, DC, in March, 1987, and at the Annual Convention of the Association for the Advancement of Behavior Therapy held in Boston, MA, in November, 1987.

The third paper, entitled "Computer Assisted Smoking Treatment: A Controlled Evaluation and Long-Term Follow-Up" is also published in the Journal of Advancement in Medicine (1992, volume 5(l), pp. 29-41). This paper is based on research conducted at an independent research institution comparing the relative effectiveness of LifeSign with and without group counseling. Eighteen-month follow-up showed CO validated abstinence rates of 36% among subjects in the group counseling condition and 24% among subjects who used LifeSign without group counseling. Portions of this research were presented at the Annual Convention of the Association for the Advancement of Behavior Therapy held in Washington, DC, November, 1989.

Results of the fourth paper, entitled "Smokers' Preference for Computer-Assisted Smoking Treatment" indicate that LifeSign is perceived as an effective and highly desirable alternative to other self-help smoking cessation programs. These results support the expectation of high efficacy rates for LifeSign, expectation regarding the effectiveness of quit smoking programs are believed to influence measured effectiveness. Portions of this study were presented at the Annual Convention of the American College of Preventative Medicine and Disease Control held in Atlanta, GA, in April, 1990.

The fifth paper, entitled "Computer Paced Rate Reductions to Decrease Nicotine and Carbon Monoxide Intake Prior to Cessation of Cigarette Smoking", is based on research done at independent research institutions. Results support the assumption that LifeSign's gradual withdrawal method of smoking cessation produces significant reductions in nicotine levels during use.

Research on the effectiveness of LifeSign for smokeless tobacco cessation was funded through a grant from the National Cancer Institute. Results showed that 29% of 62 smokeless tobacco users were abstinent four to six weeks after treatment end. Portions of this study were presented at the Society of Behavioral Medicine Convention held in New York, NY, in March, 1992. Long-term follow-up is currently in progress.