EFFECTS OF A RESISTANCE TRAINING AND DIETARY INTERVENTION ON BODY COMPOSITION IN OVERWEIGHT AND OBESE COMMUNITY DWELLING OLDER ADULTS

Background: Community-based interventions that incorporate resistance training and dietary changes have not been extensively studied in overweight and obese older adults. The purpose of this investigation was to determine the effects of a combined community-based resistance training and dietary intervention on body composition in overweight and obese older adults. Methods: Ninety-five overweight and obese (BMI = 33.4 ± 4.0 kg/m 2 ) older adults aged (69.2 ± 6.2) years completed an eight-week resistance training and dietary intervention at four Rhode Island senior centers. Participants performed resistance training twice per week using resistance tubing, dumbbells, and ankle weights. Participants also attended one weekly dietary counseling session on a modified Dietary Approaches to Stop Hypertension diet. Outcome measurements included anthropometrics and body composition. Results: There were small but statistically significant changes in body mass (-1.0 ± 1.8 kg, p<0.001), waist circumference (-5.2 ± 3.8 cm, p<0.001), hip circumference (5.3 ± 4.1 cm, p<0.001), fat mass (-0.8 ± 1.6 kg, p<0.001), and percent body fat (-0.5 ± 1.4 %, p<0.001). Additionally, no significant change was seen in fat-free mass. Conclusion: Community-based resistance training and dietary interventions can improve body composition in overweight and obese older adults. Future investigations should determine if this intervention is effective for sustaining longterm changes in older adults.


INTRODUCTION
From 1991 to 2000, the prevalence of obesity increased in the 60-69 and over 70 year old age groups by 56% and 36% respectively (1). This increase in fat mass (FM) is attributed to factors such as a decline in physical activity, reduced basal metabolic rate, and an increase in energy intake (2,3). Weight loss is recommended for obese adults who are at risk of obesity-related illness and disability (4).
Sarcopenia, the age-related reduction in skeletal muscle mass, is typically accompanied by declines in physical function and subsequent disability (5).
Additional adverse consequences of sarcopenia include difficulty with ambulation, a reduction in muscular strength, and an associated increase in adiposity (6,7).
Moreover, the deleterious effects of sarcopenia are exacerbated with obesity (8).
Previous investigations have reported a significant and independent association between fat mass and physical disability in postmenopausal women (9) and older men (10). While dietary modifications alone may elicit reductions in total body mass and fat mass, weight loss interventions for older adults are typically accompanied by involuntary decrements in muscle mass (11), which is likely detrimental to strength and function.
Resistance training (RT) has been suggested as a safe and efficacious strategy for attenuating loss of fat-free mass (FFM) during weight loss, which may be instrumental in the prevention of sarcopenia-related functional limitations (12).
However, these studies have typically used resistance exercise machines and relatively high training intensities (i.e. > 70% of one-repetition maximum). Furthermore, there is a paucity of research investigating the additive effects of RT and dietary changes in overweight and obese older adults. Recently, Fitzpatrick and colleagues (13) reported that a community-based physical activity program (i.e., chair-based exercises and walking promotion) that also promoted increased consumption of fruits and vegetables resulted in significant improvements in functional performance in older men and women. While that study provided dietary education focused on the benefits of increasing fruit and vegetable intake, dietary restriction was not implemented.
Additionally, a four-week exercise program utilizing hand weights and elastic bands resulted in significantly improved physical function in a cohort of older African-American women (14). Although these interventions improved functional abilities, the above investigations did not incorporate dietary modifications for the purpose of eliciting weight loss and only one of the studies (13) involved overweight and obese older adults. Thus, there is a need to establish the effectiveness of community-based interventions that integrate RT and dietary education on body composition in overweight older adults.
The purpose of this investigation was to assess the effects of light RT on body composition in overweight and obese, community-dwelling older adults who received a concomitant dietary intervention for intentional weight loss at four Rhode Island senior centers (two urban and two rural). We hypothesized that an eight-week intervention integrating light RT and behavioral-based dietary education would facilitate significant improvements in body composition in overweight and obese older adults. Additionally, locations were chosen based on research suggesting that education level is a predictor of socioeconomic status which is in turn an important predictor of physical activity behavior (15). Therefore an exploratory analysis was conducted to compare the rural and urban senior centers.

Study Design:
The study design was a quasi-experimental, community-based outreach intervention with baseline and post-intervention measurements. The intervention was eight weeks and comprised of two, one-hour sessions per week at two urban and two rural senior centers. Each participant provided written informed consent prior to participation and the study was approved by the Institutional Review Board (IRB) of the University of Rhode Island.
Participants: Overweight and obese, community-residing older adults aged 55-80 years (n=109) who, by self-report, were not engaged in a regular exercise program were recruited for this study. Participants were recruited via newspaper advertisements as well as flyers, brochures, and word-of-mouth at the participating senior centers. Prior to participating in this study, all participants underwent phone screening interviews, completed comprehensive medical history questionnaires. In addition, it was recommended that each participant's primary care physician also provide medical clearance. Eligibility criteria included a body mass index (BMI) between 25.0-39.9 kg/m 2 , medication-stable (within the last three weeks; > 6 months for lipid-lowering medications), and weight-stable (within 5%) during the last three months. Exclusion criteria included significant cardiovascular, metabolic, musculoskeletal, or psychological disorders that may have adversely affected the individual's ability to engage in regular exercise. Fourteen participants did not complete the study for various reasons (six lost to follow-up, five due to unrelated personal or family health issues, two due to time commitment, and one due to studyrelated adverse event of a strained muscle), which yielded an analytic sample of 95 participants. No significant differences in age or BMI existed between those participants who did not complete the study and the analytic sample.
Anthropometrics: Body mass was measured to the nearest 0.1 kg and height was measured to the nearest 0.5 cm using a standard balance beam scale (Detecto, model 439, Webb City, MO). Body mass index was calculated via weight (kg) divided by height (m) squared. Waist circumference (WC) was measured at the iliac crest using a standard 60" Gulick tape measure (Richardson, Frankfort, IL) with attached tensometer with measurements rounded to the nearest 0.25 cm and hip circumference was measured at the broadest circumference of the hips above the gluteal fold to the nearest 0.25 cm.
Body Composition: Percent body fat, FM, and FFM were measured using a battery-powered handheld bioelectrical impedance device (Omron, model HBF-306C, Bannockburn, IL) in the morning following a 12-hour fast. This device was chosen because it is portable, safe, and is both a valid and reliable measure of body composition (16). In order to minimize the risk of an adverse event, individuals with pacemakers were not tested because the device produces a small electrical current during the measurement which may have interfere with the proper functioning of the pacemaker. Fat mass was calculated as percent body fat multiplied by total body weight (kg) divided by 100. Fat free mass was calculated as total weight (kg) minus FM (kg).
Questionnaires: The Dietary Screening Tool (DST) was used to assess dietary intake. The DST is a validated, 24-item questionnaire developed to assess dietary intake and identify nutritional risk among older adults in a community setting. The DST measures overall dietary intake, assesses where a diet may be lacking or in excess of a specific macro-or micro-nutrient, and categorizes individuals into a degree of nutritional risk. Based on the DST score (range 0-100 points), subjects are categorized into one of three nutrition risk levels; <60, 60-75, and >75 place subjects in either at-risk, possible-risk, or not-at-risk, respectively. A majority of the DST questions relate to aspects of the DASH diet as questions inquire about the consumption of fruits, vegetables, dairy products, whole grains, meats and protein, fats, and sweets (23). Additionally, the Yale Physical Activity Survey (YPAS) was administered in order to estimate habitual physical activity energy expenditure.

Dietary Intervention: All participants attended one 30-minute behavioralbased dietary session during each week of the intervention. A modified Dietary
Approaches to Stop Hypertension (DASH) diet was implemented immediately following baseline testing and participants were instructed to adhere to these recommendations for the duration of the intervention. The DASH diet encourages reduced consumption of saturated fat, increased consumption of fruits and vegetables, reduced consumption of dietary sodium, and the accumulation of ~ 180 minutes of moderate-intensity physical activity each week (17). The DASH diet was modified for this investigation by placing an increased emphasis on consumption of unsaturated fatty acids and limiting total fat intake to less than 35% of daily caloric consumption, rather than the less than 27% recommended by the original DASH guidelines because unsaturated fatty acids may possess advantageous cardio-protective properties (18).
Dietary education topics included reading and understanding food labels, estimating portion sizes, and behavioral strategies for increasing consumption of fruits and vegetables and how to self-monitor. All dietary classes were conducted by a registered dietitian.
Resistance Training Intervention: All participants completed two 30 to 45 minute sessions of supervised RT on non-consecutive days of the week for eight weeks. Participants performed RT exercises using hand-held dumbbells, elastic tubing, and ankle weights. Three upper-body (chest press, shoulder press, and back row) and three lower-body (leg press, knee extension, and leg curl) exercises were completed during each training session and three sets of 8-12 repetitions were performed for each exercise. This specific repetition assignment was chosen because 8-12 repetitions performed to volitional fatigue is recommended for optimizing muscle strength and is in accordance with physical activity guidelines published by the American College of Sports Medicine (19). Each participant's individual progression was monitored by study staff and resistance was increased when the participant was able to complete > 12 repetitions for a particular exercise with proper form.
Participants were instructed to perform a ~ 1 s concentric phase of each exercise, with a ~ 2-3 s eccentric phase. Comparable RT protocols have been successfully implemented in similar cohorts and have been shown to be effective at improving strength and function (13,20). In order to monitor intensity, participants were introduced to the rating of perceived exertion scale and were instructed to subjectively monitor the difficulty of each exercise based on this scale. Exercise intensity was designed to be "somewhat hard," which has been shown to be effective at facilitating an increase in physical function (21). Past studies have indicated this intensity is tolerable in geriatric populations (22), resulting in greater adherence to exercise programs (23). Study staff was trained by the principal investigators and those proficient with the exercise protocol supervised all RT sessions.

RESULTS
Participant characteristics at baseline, post-intervention, and change from baseline to post-intervention for the analytic sample are presented in Table 1  Therefore with an aging population the prevalence of obesity in older adults is likely to increase, thus obesity represents an urgent public health matter for the elderly population. Weight loss is recommended for obese adults who are at risk of obesityrelated illness and disability (Villareal, Apovian et al. 2005).
Excess body fat is associated with many negative health consequences in older adults including cardiovascular disease, metabolic syndrome, dyslipidemia, knee osteoarthritis, urinary incontinence, breast cancer, cataracts, and pulmonary function abnormalities (Riebe, Blissmer et al. 2009). In addition to these negative health outcomes an association between overweight and obesity and an increased risk of functional limitations in older adults has also been reported (Ensrud, Nevitt et al. 1994 identified it is of major public health concern to find effective strategies to intervene to prevent this negative symbiotic relationship. The following studies sought to identify the relationship between obesity and functional limitations.
Visser and colleagues analyzed data from the Cardiovascular Health Study to examine the relationship between body composition and self-reported mobility-related disability in a cohort of men and women aged 65-100 years of age. Body composition was assessed using bioelectrical impedance analysis and mobility-related disability was measured via the self-reported ability to walk 0.5 miles and climb 10 stairs. After adjustment for potential confounders, increased FM was associated with a two-to three-fold greater likelihood of mobility-related disability during a three-year followup period. These results suggest that excessive FM is an independent predictor of mobility-related disability among community-dwelling elderly men and women.
While this study determined a relationship between FM and function, other studies have found a similar relationship between BMI and function (Visser, Langlois et al.

1998).
Zoico and colleagues also investigated the relationship between obesity and physical disability in community-dwelling women aged 67-78 years. Body prevention is sarcopenia, and even more so the combination of sarcopenia and obesity.

Sarcopenic-Obesity
Sarcopenia is defined as the age-related loss of muscle mass (Rosenberg 1997).

Dietary Weight Loss
Obesity has been reported to exacerbate declines in functional abilities, reduce quality of life, and increase the likelihood for institutionalization in older adults ). Therefore, intentional weight loss may exacerbate the sarcopenia-related decline in skeletal muscle mass that is typically evident in older adults due to accelerated loss of FFM. Traditional weight loss diets which achieve weight loss via low fat intake can be of concern, especially in an older population, because of the decreases in lean muscle mass and the negative impact on some lipoprotein measures (Delmonico and Lofgren 2010). Therefore, when inducing weight loss in an older obese population the importance to focus on the need for a well balanced diet may be further amplified.

Dietary Approaches to Stop Hypertension
Compliance with the DASH diet improves diet quality and lowers CHD risk by decreasing systolic and diastolic blood pressure ( Participants were randomly assigned to either a control group that performed a low intensity home exercise program or to a supervised exercise training group which performed three months of low intensity exercise and three months of progressive RT.
The participants randomized to the home exercise control group were asked to exercise at home two to three times per week completing nine exercises which focused

Community-Based Resistance Training plus Weight Loss Interventions
Although  daily living will be assessed during this first phase. These activities of daily living tasks include rising from a chair, standing balance tests, and short (4-meter) brisk walks. Any risk of injury during the completion of these tasks will be minimized by having all sessions supervised by an exercise physiologist qualified to direct this type of testing. In addition, you will be asked to complete several questionnaires. These include the National Cancer Institute fat screener questionnaire, a food behavior checklist, a physical activity survey, and a general health survey.
You will also complete two finger sticks that will be used to analyze blood sugar, fats, and C-reactive protein (CRP, a blood protein associated with heart disease risk). Analysis of blood will be conducted using a portable Cholestech machine. For the twelve hours prior to the finger sticks, you will be asked to refrain from eating and/or drinking anything, unless it is plain water. For example, if your finger sticks are scheduled for 10:00am on a Wednesday, you are asked to not eat and/or drink anything besides plain water after 10:00pm on Tuesday evening. We do encourage you to drink as much plain water as you would like. The total amount of blood drawn for these tests over the course of the study will be equivalent to less than one teaspoon.
You understand that trained personnel, using universal precautions and established methods, will conduct the two fingersticks. You understand that the two fingersticks require a very small amount of blood. You understand that there is a risk of bruising, pain, and in rare cases, infection or fainting as a result of blood sampling. However, these risks to you will be minimized by allowing only qualified people to draw your blood.
You understand that strength assessments will be performed using portable devices that measure how much force you can exert force through a typical knee extension motion and your grip strength. You understand that you may experience some temporary muscle soreness as a result of the muscle testing. There is also a risk of muscle soreness or skeletal injury from strength testing as well as from resistance training. The investigators of this study will use procedures designed to minimize this risk.
Your percent body fat will be performed using bioelectrical impedance analysis, which is a battery powered, portable, handheld device that uses a very low electrical current (~ 50 kHz) in order to estimate fat mass and percentage body fat. This test only takes about 10 seconds to complete but is a valid and reliable measure of body composition with very few risks. Even though the risk is low, as a precaution, individuals with a pacemaker will not be tested on the bioelectrical impedance analysis device.
During phase two, you understand that you will be responsible for arriving for intervention group meetings at your senior center two times weekly (days and times vary depending on which senior center you attend), during the time allotted. You will participate in a dietary education program designed to produce a moderate weight loss of 5-10 pounds (about 3-5% of your current weight). You will be encouraged to consume a well-established, lower calorie, balanced diet in which the goal will be to reduce your food intake by about 500 calories per day. You will meet as a group with an expert in nutrition once per week (~ 30 minutes per session following one of your exercise sessions) for ~ 10 weeks who will give you instructions and expert advice on food selection, preparation, and overall lifestyle changes. Your weight will be monitored weekly in order to determine weight change.
In addition, during phase two you will be asked to participate in two (2) supervised exercise sessions per week (~ 30-40 minutes per visit) for the ~ 10-week program. During these sessions, you will receive instructions from trained exercise staff and will undergo resistance exercise training for all of your major muscle groups. Your progress will be monitored and you will always be instructed by an exercise specialist regarding proper use of the equipment and exercise techniques. No special clothing is required. You will also be instructed to stop exercising immediately if you experience chest pain, muscle injuries, or any other unexpected symptoms. Although you will always have supervision when doing resistance exercise training during this study, if you ever experience chest pain while exercising at other times, you should immediately call 911 to seek emergency care and notify your primary care physician. If you have any problems or injuries, you should also notify a member of the study team. Study team members and their phone numbers are noted on the first page of this consent form.
You will be asked to exercise using basic resistance exercise training equipment (e.g. rubber bands, hand and ankle weights), which offers resistance against extending and flexing your arms, legs, and trunk region for approximately 40 minutes or less a day. All sessions will start with a brief warm-up. The first several resistance training sessions will begin with lighter resistances to get you used to the resistance training program. Your blood pressure will also be monitored before and after each training session. Your overall progress will be monitored by an exercise specialist so that you are able to tolerate the exercise.
During phase three, you will repeat the measures that we took during the first phase including height, weight, blood pressure, body composition, muscle strength, ability to complete selected tasks, and questionnaires. You will also complete two more fasting finger sticks (on the same day) that will be used to analyze blood sugar, fats, and CRP.

Risks or discomfort:
You understand that it is also possible that heart or blood vessel problems could arise during your participation in the testing or training involved in this study. Although highly unusual, it is possible that these problems could lead to a heart attack or even death. Therefore, prior evaluation and written clearance with a signature from your personal physician will be strongly encouraged for you to participate in this study. You also understand that it is possible that these risks will not be eliminated completely, even with a medical evaluation prior to participation in the study. However, the investigators believe the risk of harm from study participation is small and that the benefits of the study will likely outweigh any potential risks.

In case there is any injury to the subject:
In the event of physical injury resulting from participation in this study, upon your consent, emergency treatment will be available at the nearest local hospital with the understanding that any injury that required medical attention becomes your financial responsibility. You understand that the University of Rhode Island at Kingston will not provide any medical or hospitalization insurance coverage for participants in this research study, nor will they provide compensation for any injury sustained as a result of this research study, except as required by law.
You understand that if you are injured while participating in this research project as a result of negligence of all state employees who are involved in this research project, you may be able to be compensated for your injuries in accordance with the requirements of the Federal Tort Claims Act. If you are a federal employee acting within the scope of your employment, you may be entitled to benefits in accordance with the Federal Employees Compensation Act.

Confidentiality:
You understand that all information collected in this study is confidential, and your name will not be identified and linked to any study data at any time to anyone other than the PIs of the study. All study data, including this consent form, will be locked in a file cabinet and also stored in a study computer with a password secured in our study office (25 West Independence Way, room 225, Kingston, RI 02881).

Benefits of this study:
You understand that although this study may help you personally, it may also help the investigators better understand which interventions are the most effective in helping overweight and obese older adults improve their physical function, body composition, and heart disease risk factors. Because of what is already known regarding the individual effects of dietary education for weight loss and resistance exercise training, it is likely that you will notice some benefits. These potential benefits include increased understanding of nutrition, a reduction in overall weight and body fat, and improved mobility.
For your participation in the study and after the study is completed, you will receive, free of charge, information about your blood pressure, blood test results, body composition, muscle strength and power, physical function, and you will be paid in two $25 local supermarket gift cards.

Decision to quit at any time:
You understand that is your decision and your decision alone whether or not you consent to participate in this study. You understand that you are free to ask questions about this study before you decide whether or not to consent to participate in it. You understand that if you consent to participate in the study you are free to withdraw from participation at any time without penalty or coercion, or without any requirement that you provide an explanation to anyone of your decision to withdraw.

Rights and Complaints:
If you are not satisfied with the way this study is performed, you may discuss your complaints with the principal investigators, Drs. Matthew Delmonico at (401)  Although we are unaware of any cardiac complications that have resulted from strength testing or resistance exercise training, there is only limited amount of data available in older adults. There is one report of non-fatal subarachnoid hemorrhage associated with strength training in three patients who had pre-existing intracranial aneurysms. For this reason, any patient who has known or suspected intracranial aneurysm or who is at high risk for having an intracranial aneurysm should not participate in this study.
Please check one of the following: ___ Clearance granted ___ Clearance not granted ___ Please send me the following information about the study: Volunteers in this study will participate in a 10-week lifestyle modification program for weight loss and might participate in resistance exercise training under the supervision of exercise specialists trained specifically for this study under the direction of the Principal Investigators, Matthew J. Delmonico