Of 79 overweight adults with intellectual or developmental disabilities who participated in a weight loss intervention, 73 completed the 6-month diet phase. The emphasis in the intervention was consumption of high volume, low calorie foods and beverages, including meal-replacement shakes. Lower calorie frozen entrees were recommended to control portion size. A walking activity was encouraged. Participants attended monthly meetings in which a small amount of cash was exchanged for self-recorded intake and exercise records completed on picture-based forms. Average weight loss was 13.2 pounds (6.3%) of baseline weight at 6 months, with weight loss shown by 64 of the 73 individuals enrolled. Those completing a 6-month follow-up phase showed weight loss of 9.4% of baseline. Increased choice and control are discussed as possible contributors to individual success.
In this paper we report the results of an evaluation of a novel approach to establishing healthy food and beverage consumption in adults with intellectual or developmental disabilities. The intervention grew out of a response to a request for proposals from the Kansas Council on Developmental Disabilities. The Council's goal was to reduce the incidence of overweight and obesity in this population in Kansas by 5%. As researchers interested in this goal, we responded to the announcement, obtained the grant, and conducted the investigation. We merged current dieting strategies for persons without disabilities with effective strategies for communicating with and motivating adults who have disabilities. We did not use a control group. As discussed below, the standard diet or usual care diet has not been effective with this population. Thus, funding additional individuals on that diet was not an important objective. Rather, our purpose was to determine whether there might be an alternative with promise—an alternative that could subsequently be compared with the usual care approach in a randomized trial.
Obesity is a chronic disease defined by a body mass index (BMI) of 30 or greater. Current estimates indicate that 31% of adults in the United States are obese. The combined percentage of adults in the United States who are overweight and obese (BMI > 25) is approximately 65.7% (Ogden et al., 2006). Estimates suggest that overweight and obesity are associated with over 365,000 deaths each year (Mokdad, Marks, Stroup, & Gerberding, 2004, 2005) and health care costs of $78.5 billion in 1998 ($92.6 billion in 2002 dollars) (Finkelstein, Fiebelkorn, & Wang, 2003)
In a systematic review of 12 articles on the prevalence of obesity in individuals with intellectual and developmental disabilities, Melville, Hamilton, Hanky, Miller, and Boyle (2007) showed that the prevalence of obesity was 2.1 times higher in these individuals compared with the general population. Rimmer, Braddock, and Fujiura (1993), who evaluated the impact of living arrangement on the prevalence of obesity, found that the obesity prevalence increases with less restrictive living arrangements (institutions = 16.5%, intermediate care facilities = 50%, group homes = 40.9%, at home, 55.3%). Prevalence data indicate that individuals with Down syndrome have a significantly higher incidence of obesity, especially those living with family (Rubin, Rimmer, Chicoine, Braddock, & McGuire, 1998). Females also are more than twice as likely to be obese than are males (Rimmer et al., 1993).
Obese individuals in the general population show higher rates of total mortality (Fontaine, Redden, Wang, Westfall, & Allison, 2003), heart disease (Grotto, Huerta, Kark, Shpikgerg, & Meyerovitch, 2003), hypertension (Carnethon et al., 2003; Neter, Stam, Kok, Grobbee, & Geleijnse, 2003), social stigmatization (National Heart, Lung, and Blood Institute, 1998), and some cancers (Evenson, Stevens, Cai, Thomas, & Thomas, 2003; Parker & Folsom, 2003). The association between Type II diabetes and obesity also appears quite strong. Approximately 80% of Type II diabetics are overweight (Hensrud, 2001), and the increased prevalence of Type II diabetes has been concurrent with the increased prevalence of obesity (U.S. Department of Health and Human Services, 2001). The rates of comorbid diseases associated with obesity, such as cardiovascular disease, are higher in our target population compared with the general population (Beange, McElduff, & Baker, 1995).
The increase in prevalence of obesity has been associated with a lack of physical activity in both the general population (Hu, Li, Colditz, Willett, & Manson, 2003) and our target population (Beange et al., 1995; Draheim, Williams, & McCubbin, 2002; Rimmer, Braddock, & Marks, 1995). Individuals living with family or in supported living arrangements are less physically active when compared with their peers living in institutional settings (Beange et al., 1995; Draheim et al., 2002; Rimmer et al., 1995). According to Draheim et al. (2002), 47% and 51% of men and women, respectively, in supported living report little or no leisure time physical activity. Environmental barriers to physical activity appear to be greater for this population compared with the general population and include financial constraints, limited geographical access, and limited choices (Messent, Cooke, & Long, 1999).
Increasing rates of obesity and health problems have produced an outcry from advocates for persons with a disability. This outcry led to several position papers on behalf of people with special needs. In chapter 6 of Disability and Secondary Conditions of Healthy People 2010, the authors stated:
[Misconceptions about disability have] led to an underemphasis of health promotion and disease prevention activities targeting people with disabilities and an increase in the occurrence of secondary conditions (medical, social, emotional, family, or community problems) which a person with a primary disabling condition is likely to experience. (U.S. Department of Health and Human Services, 2000, p. 4)
The Department of Education, National Institute on Disability and Rehabilitation Research, has issued a list of proposed priorities, and reducing obesity and obesity related secondary conditions in adolescents and adults with disabilities is a priority (U.S. Department of Education, 2006). In addition, the Surgeon General's Report on Health and Wellness of People with Disabilities (U.S. Department of Health and Human Services, 2005) encourages increased efforts to decrease the incidence of obesity among children, adolescents, and adults with disabilities.
Although the problem of the high prevalence of obesity in individuals with disabilities has been recognized, there is currently limited evidence-based information on which to develop effective treatment programs. Hamilton, Hankey, Miller, Boyle, and Melville (2007) recently reported a systematic review of eight studies in which researchers evaluated weight loss interventions for individuals with intellectual and developmental disabilities. The average sample sizes were small (n = 17, range = 4 to 50), with six of the eight studies including less than 25 participants in the treatment group. Only one weight loss study reported follow along for as long as one year. The average duration of the seven other studies was 11 weeks (range = 7 to 19). Interventions involved the promotion of healthy eating rather than a specific level of energy restriction in six studies, while increases in physical activity were the focus of two studies. Results indicated a mean weight change from +1.54 pounds (0.7 kg) to −7.5 pounds (3.4 kg). Researchers in four studies reported data at 6 and 12 months following the active intervention, with results ranging from a weight loss of approximately 4.4 pounds (2 kg) to weight gains of up to 6.61 pounds (3 kg). Thus, both weight loss and weight maintenance reported in these studies was ∼1.5% to 3% from baseline, and this is considerably less than the National Heart Lung and Blood Institute (1998) guideline of 10% weight loss and maintenance and below that shown in the Diabetes Prevention Program, which was 7% (Knowler et al., 2002).
In a review of nutrition of persons with intellectual and developmental disabilities, Humphries, Traci, and Seekins (2009) made several recommendations for researchers interested in the topic. They suggested (a) that diet researchers and behavioral science experts work together to develop tools to gather information about nutrition habits of those with intellectual and developmental disabilities and (b) that “effective nutrition education and supports must build on the individual's social network, and nutritional teaching materials must be interactive and visual, and culturally appropriate” (Macario et al., 1998, cited in Humphries et al., 2009, p. 177). Further, health promotion strategies should include decision-making and self-determination (Sutherland, Couch, & Iacono, 2002).
The diet and physical activity program described below incorporated many of the recommendations of Humphries et al. (2009). The project was the cooperative effort of a group of researchers who have extensive experience studying the effects of diet and physical activity in children and adults without disabilities, and researchers who have had extensive experience teaching individuals with disabilities and training their support staff. The intervention has features that are visual and simple to follow. The diet allows layers of choice-making, promotes independence, and incorporates a tiered incentive system. Our research hypotheses were that (a) adults with intellectual and developmental disabilities could learn to follow a simplified diet scheme and (b) those who did would lose weight.
Participants and Enrollment
Ninety-four adults, ranging in age between 18 and 62 years, responded to recruitment notices by contacting a member of the research team. Fifteen elected not to participate. The remaining 79 participated in the project for at least one month. All were in the overweight or obese range. Diagnosis of a genetic metabolic disorder, such as Prader-Willi syndrome, Type I diabetes, cancer, heart disease, or other debilitating illness, was ruled out through conditions of physician release to participate. All participants or their caregivers also indicated that they received state funds through the Home and Community Based Services developmental disability waiver program or had had been enrolled previously in special education classes. All were verbal but varied in their memory and communication abilities. We did not administer any formal tests of cognitive functioning. The physician's release was required prior to beginning the diet. Those who wished to participate in the physical activity component of the intervention also required a physician's release specific to the physical activity component. All procedures were approved by the University's Human Subjects Committee. Participants and/or their guardians signed a consent for research participation. Participants also gave verbal assent at enrollment and were asked to repeat their assent monthly throughout the study.
The initial meeting to introduce and explain the diet was 60 to 90 min in length and was conducted individually with each participant. The researchers explained that the project consisted of a 6-month diet phase and a 6-month follow-up phase. If an individual decided to enroll, we obtained baseline data through interview and examination. These data included height (for BMI), weight, waist circumference, a recall of foods and beverages consumed in the preceding 24-hr period, current medications, recent history of attempts to lose weight, living arrangement, and other demographic variables. Subsequently, a member of the research team met with each participant monthly in a meeting that averaged about 30 min. Monthly recall duties rotated unsystematically across two exercise physiologists, a registered dietician, and two behavior analysts, all of whom had achieved pre-experimental interinterventionist reliability in measuring height, weight, waist circumference, and 24-hr intake recall methods. During monthly meetings, weight and waist circumference were recorded, a 24-hr recall of intake was obtained, praise and other incentives were given for weight loss, problems related to staying on the diet or any physical complaints were discussed, and suggestions were shared. More information about what occurred during monthly reviews will be discussed later in the Monthly Meetings section.
The recommended diet was based on the concept of volumetrics; that is, the consumption of high volume foods should provide the sensation of fullness (Rolls, 2003). High volume foods have high water and fiber content. Fruits and vegetables and water-based soups are examples. Many meal replacement shakes also are high volume. The diet is one that had been tested extensively and proven effective with adults without disabilities (e.g., Ditschuneit & Flechtner-Mors, 1996). The participants were instructed that the diet, with intake of 1200 to 1300 calories per day, consisted of (a) at least five servings of fruits and vegetables (fresh, frozen, or canned); (b) up to three low-calorie, meal/snack-replacement shakes; (c) two packaged entrees of less than 300 calories each (from the frozen food section of a local grocery store); and (d) other low calorie items.
Shake mixes from Health Management Resources (HMR®) were donated by the company and two per day were offered free of charge. Other drinks and shake mixes were discussed as well. The HMR shake mix provided 110 calories per serving when mixed with water, could be mixed with fruits or seasonings, and provided a feeling of fullness that maintained for several hours. Shakes were emphasized in this diet not only because of their volumetric effect but because they are easy to prepare. Some participants either did not like the shakes or did not always want to prepare them. Unsweetened cereal with fruit and skimmed milk was suggested as a substitute breakfast. Similar to the shakes, frozen entrees required little time or expertise to prepare, offered a wide range of choices, were relatively inexpensive, and, most importantly, controlled portion size. Lists of examples from Lean Cuisine®, Lean Gourmet®, Smart Ones®, and Healthy Choice® were provided. Entrees from HMR®, Weight Watchers®, Nutri-System®, Jenny Craig®, and other companies were suggested as alternatives to grocery brands. A list of entrees or sandwiches from local restaurants and fast-food locations with less than 500 calories (taken from Internet sources) was also provided as a guide to adhering to the diet while eating out.
At the initial meeting, we reviewed a list of food items, beverages, and prepared meals (e.g., Mexican) with the participant to determine food likes and dislikes. The few participants who were unable to respond completely independently were assisted by a caregiver. The food and beverage items identified as preferred were categorized according to calories consumed in an average single portion.
The most preferred items were organized into a visual aid called a Stoplight Guide (Epstein & Squires, 1988). Stoplight Guides were prepared in either pictorial or written form, depending on the participant's reading ability. Items that were about 60 calories or less were coded with a green dot beside the label or beside the label and picture of the item (for nonreaders). Those between 60 and 100 calories were coded with a yellow dot, and those above 100 calories were assigned a red dot. Meats were scored slightly differently, but according to calorie content. The participants were told to “eat all you want of green items, to use moderation on yellow items, and to avoid red items.” We informed participants that red light items were acceptable as long as they were the contents of a frozen entrée under 300 calories. Participants were encouraged to refer to the Stoplight Guide when making a shopping list and to take it with them when they went grocery shopping. They also were prompted to refer to the Guide when they wanted to have a snack or meal not on the regular diet.
The food preference assessment, sample Stoplight Guide, entrée and meal suggestions, and the other materials described below may be viewed and downloaded (KU Diet Project, n.d.).
Data Collection and Incentives
Shortly following the first meeting with a participant, we provided each participant with charts for self-recording weight. The personalized Weight Chart was in the form of columns of 20 numbers, ranging from a pound or two above their baseline weight at the top to about 18 pounds below baseline weight. A column represented one day, and each chart had 14 columns (for 2 weeks). A number was circled in the first column to indicate the baseline weight and two BMI levels below the current BMI range were shown in contrasting colors. Participants were encouraged to weigh themselves every day, at the same time of day if possible, and circle the number corresponding to that day's weight in the column for the designated day of the week. Completing the chart in this way produced a graph-like picture (Saunders & Koplik, 1975) of weight loss. Daily weighing was conducted on the participant's personal scale, if he or she had one, or on a support agency scale. A scale was purchased by project personnel for those without one who wanted to weigh daily.
Intake tracking forms
Forms for self-recording energy intake and output were provided at each monthly meeting. The front and back of each form depicted a total of seven columns of icons, one column for each day of the week. Each icon was a colored representation for fruit, vegetables, entrees, diet shakes, snacks, or exercise. Each column depicted three bunches of carrots (representing any vegetable), two apples (representing any fruit), three blenders (representing a shake), two piping hot entrees (representing the less than 300 calorie dinner), and a tennis shoe (representing any form of exercise). The column also depicted a red stoplight (representing any off-diet red snack or entree) and a green stoplight (representing any additional low-calorie snack). Participants were instructed to enter a mark beside or on each icon for each food or beverage consumed. They were instructed to mark the tennis shoe if they exercised and to enter what type of exercise and for how long next to the shoe icon.
Participants who elected to participate in the physical activity component of the intervention were provided with a game board, step counter, and dry-erase marker. The game board was a laminated poster that could be written on with the marker and erased if needed. The poster resembled other game boards, with a pathway of circles leading to islands. Each circle represented 10,000 steps. Each island was labeled 100,000 steps, and the final island was labeled 1,000,000 steps. Participants were encouraged to wear the step counter to keep track of their daily step count, write their count on the tracking form, and mark progress on the game board with the marker.
Twenty-four hour recalls
At monthly meetings, the participant was asked to recall every food and beverage he or she had consumed in the previous 24 hrs, how much of each was consumed, how the food was prepared, any seasonings or condiments applied, and the time and location of eating and drinking. The interviewers used their hands to show samples of portion sizes, bowl sizes, heights of glasses, thickness of chicken breasts, and so forth to help participants provide a reasonably accurate report. For entrees, the brand name or the color of the entrée box was requested, as well as its contents if remembered. The colors of the P.M. boxes reflected brands (e.g., green for Healthy Choice®, red for Smart Ones®) and then discussion about the brand often prompted recollection of the contents (e.g., Beef Tips Portabello, Slow Roasted Turkey Breast). A dietician entered the recall into the Nutrition Data System for Research (2008) software and reviewed the recall for nutritional composition and caloric intake. This information was used as needed at subsequent monthly meetings, combined with the self-recorded data, to serve as a guide for making suggestions to the participants for improving their success, or to give positive feedback for their high degree of compliance with the diet.
At monthly meetings, we paid 5 cents in cash for each icon marked on the tracking forms for on-diet foods or exercise. An additional 5 cents per item was deposited in a “savings account.” The account would to be paid at the end of the 6-month diet phase or immediately upon withdrawal from the study. However, if at any monthly meeting, a participant's weight had decreased by one BMI point, the cumulative amount in the savings account was paid immediately. Also, $5 was paid for each 100,000-step island attained on the game board by walking and charting progress during the month. A certificate of personal accomplishment was given to each participant for losing the first BMI point reduction. A Jayhawk (mascot of the University of Kansas) sticker, to place on the certificate, was offered for each additional BMI point reduction.
Participants also used monthly meetings to ask for advice of various kinds, such as what to eat at a planned family Thanksgiving dinner, whether a certain food was green light or not, or to discuss issues arising in their residences that might bear on their diet. Research staff provided suggestions and ideas designed to assist participants with their questions and to reward them for seeking counsel. At the end of each monthly recall meeting, the participant was provided with a “bragging card.” The cards were the size of typical business cards and contained a Jayhawk. In the appropriate spaces, the interviewer recorded the number of pounds lost (if any) since the previous meeting and the total pounds lost since enrollment.
Conclusion and follow-up
At the conclusion of the 6-month diet phase, we provided guidance on where in the daily diet calories could be added to prevent further weight loss but avoid gaining weight. Those who desired to lose more weight were encouraged to keep doing what had been successful up to then. Regardless of choice, the participants began a 6-month follow-up phase in which the monthly meetings with 24-hr recalls continued. During this phase, we did not request self-recordings of intake and exercise, no longer provided shake mixes and Jayhawk stickers, and did not give incentive payments based on intake and output reports. Instead, each participant received $20 for attending and participating in the recall meeting. We continued giving bragging cards for those attempting to lose additional weight.
During the follow-up phase, we distributed a survey to the participants and arranged methods for it to be completed and returned anonymously. The survey probed for the impact of the project on the participants and their quality of life as well as whether the researchers had treated them with respect. For those unable to read, we asked that a staff member or parent read the questions, but allowed the participant to respond to them
The average BMI of the 79 adults who enrolled and participated for at least one month was 38.0. Of the 54 participants who provided details of their medications, 26 were on at least one that had weight gain as an adverse side effect. Seventy-three individuals (92%) participated for the entire 6-month diet phase. The 6 who did not complete the diet phase participated for an average of 3.3 months and lost an average of 7 pounds (3.2 kg) or 2.8% of baseline weight. The 73 participants who completed the diet phase had an average weight loss of 13.12 pounds (6.0 kg) or 6.3% of baseline or roughly 2.7 BMI points. Energy intake estimated from 24-hr recalls was reduced from an average of 1660 kcal/d at baseline to 1375 kcal/d at 6 months. Forty-seven participants (62%) chose to participate in physical activity and the majority used walking. From the weekly self-reports, the average amount of physical activity over the 6 months intervention was 156 min per week. No injuries related to physical activity were reported. Weight loss, living arrangement, diagnosis, and gender for the 73 participants who completed the diet phase are summarized in Table 1.
To get insight into what aspects of the diet contributed most to weight loss, we analyzed all recall and weekly self-reported intake data for the 10 participants who lost the most weight during the 6-month diet phase. These individuals had an average daily intake at 6 months of 1221 calories and lost an average of 32.7 pounds (14.9 kg). Across the 6 months, their daily average use of a shake or shake plus fruit as a replacement for breakfast was 0.8 compared with the recommended 2 daily. The average consumption of a frozen entrée was 0.6 at each meal or 1.2 per day as compared to the 2 recommended daily. Overall, the rate of intake of on-diet items (shakes, frozen entrees, portion-controlled other entrees, fruits, vegetables, and green light snacks) was 8.1 per day and the rate of intake of red light items, 1.5 per day, a ratio of 5.4 low-calorie items per 1 high calorie item. Thus, although not reporting that they followed the diet precisely as recommended and consuming red light items, these individuals managed to lose considerable weight. With these very successful participants, as with all our participants, the accuracy of their various self-reports (e.g., tracking forms) could not be independently verified. However, their weight loss was independently verified; thus, we conclude that there was some relatively high degree of accuracy in their self-reports.
Forty-three of the 73 participants who finished the diet phase remained enrolled in the project through the entire 6-month follow-up phase. The remainder withdrew during the follow-up phase for various reasons, including moving away, joining a different diet plan, losing transportation, and a lack of interest in further meetings. In the follow-up phase 29 of 43 individuals continued to lose weight; 14 regained some weight. Only 4 of 43 regained as much or more than they had lost. The average cumulative weight loss for the 43 completing the follow-up phase was 19.40 pounds (8.8 kg). The range for this group included weight gain of 12.79 pounds (5.8 kg) to as much as 51.15 pounds (23.2 kg) lost. This represents a range over baseline weight of 8.73% gained to 28.1% lost. We attempted to deliver a copy of the survey to all participants completing the 6-month diet phase; 68% were returned. The results, shown in Table 2, indicate a high degree of satisfaction with the project and its perceived benefits.
The study was a pilot investigation of a diet and physical activity program for adults with intellectual and developmental disabilities. The foods contained in the diet were inexpensive and easy to prepare. The instructional materials were visual and required no understanding of calories. Over 85% of the participants lost weight during the diet phase. The results are encouraging and exceed the minimum 3% weight loss suggested as clinically relevant (Donnelly et al., 2009). The average weight lost after 6 months on the diet was close to the recommended 7% weight loss of the Diabetes Prevention Program (Knowler et al., 2002).
Our results suggest that persons with intellectual and developmental disabilities do care about their health. They can be recruited into a diet and physical activity study, will follow diet and activity protocols, and can lose weight. It is not yet known whether these participants can maintain that weight loss after discontinuing the monthly meetings. The results also suggest that the diet and physical activity approach is successful with both males and females and those with Down syndrome. No participant mentioned cost as a problem in participation or adherence to the diet.
A critical factor in the success of this particular diet intervention may have been the increased opportunity for choice and self-determination on the part of the participant (e.g., they were allowed to select their entrees and preferred fruits and vegetables). Consistent with the current concept of self determination for adults with intellectual and developmental disabilities (Wehmeyer, 1992), agencies that serve them typically promote empowerment of lifestyle choices, such as how to spend free time and what to buy with extra spending money (Lakin et al., 2008). Indeed, it has been assumed that the obesity epidemic in persons with intellectual and developmental disabilities has arisen from a long and continuing history of poor choices about what and how much to eat. The present results suggest that adults with intellectual and developmental disabilities can learn to make better choices.
Studies are needed to systematically examine the roles of choice and self-determination in weight loss interventions with people who have intellectual and developmental disabilities. The present results also need to be replicated. Further, the procedures should be compared to a standard diet approach in a large-scale, randomized trial. The effects of weight loss on blood pressure, triglycerides, and cardiovascular fitness should be measured. Exercise needs to be assessed using accelerometry measures.
In summary, the present intervention produced a clinically significant weight loss in a majority of the participants, a finding not previously reported with adults in this population. Moreover, most sustained or continued their weight loss for 6 months after the diet phase of the study, a finding seldom reported for adults without intellectual and developmental disabilities. Given the epidemic of obesity in this population, there is a pressing need for replication of our results and analysis of our methods.
This project was funded by the Kansas Council on Developmental Disabilities, the Administration on Developmental Disabilities, and the University of Kansas. Special thanks is extended to all service agencies, case managers, and parents who invited us to work with those they support. We are particularly appreciative of the assistance extended by the Kansas Elks Training Center, Wichita, KS, over nearly 15 months. The authors also extend special thanks to Health Management Resources (HMR®) for its generous donation of the many shake mixes.
Editor-in-Charge: Steven J. Taylor
Richard R. Saunders, PhD (firstname.lastname@example.org), Senior Scientist; Muriel D. Saunders, PhD, Assistant Research Professor; Joseph E. Donnelly, EdD, Professor and Director of the Center for Physical Activity and Weight Management; Bryan K. Smith, PhD, Assistant Research Professor, Center for Physical Activity and Weight Management, Schiefelbusch Institute for Life Span Studies, University of Kansas, 1052 Dole Bldg., 1000 Sunnyside Ave., Lawrence, KS 66045. Debra K. Sullivan, PhD, RD, Associate Professor and Chair, School of Allied Health, Dietetics, and Nutrition, University of Kansas Medical Center, Kansas City, KS 66160. Brianne Guilford, MS, Research Assistant, and Mary F. Rondon, MS, RD, Research Assistant, Center for Physical Activity and Weight Management, Schiefelbusch Institute for Life Span Studies, University of Kansas, 100 Robinson Gym, Lawrence, KS 66054.