Study Procedures
The weight loss program is 17-weeks in duration and is comprised of specialists such as a Program Manager, Physician, RD, CCPT, and CPA/CBT. The team of specialists will collaborate together to prescribe a plan best suited for the participants' needs. Since the weight loss program is based on sustainable lifestyle changes, all aspects of an individuals’ life are considered (i.e. lifestyle, sleep, mental health, behaviours).
The aims in the first week of the program are to get to know the participants, what they are looking to achieve, assessing their stage of readiness to change, and being assessed individually by each discipline on the team. The Program Manager will complete an initial assessment on the participant, this includes completing questionnaires relevant to the program (Stages of Change questionnaire(9), the WI Health Screening questionnaire, Beck’s Depression Inventory and Beck Anxiety Inventory(10) and an Initial Assessment questionnaire created by the WLC team). The CCPT will then collect anthropometric measurements, body composition (assessed by the InBody 570), blood pressure, and provide a lab requisition for the participant to collect a lipid profile (such as total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein cholesterol, triglycerides, total cholesterol/HDL, hemoglobin A1C). As well, an aerobic and strength assessment will be conducted. Afterwards, the participant will meet with the CPA/CBT and RD for an initial assessment.
The second week of the program focuses on nutrition. A dietary prescription, which involves a meal plan focused on whole foods with an emphasis on a plant-based diet will be given to the participant. Although the dietary prescription is based on a combination of DASH and the Mediterranean dietary patterns (11)(12), diets are individualized to the participants' food beliefs and preferences. A DASH diet consists of a diet high in fruits and vegetables, lean meat and dairy products, and minimally processed foods (11). Psychological intervention may be replaced with diet intervention at this stage if the participant screens for severe depression, anxiety, disordered eating or present with any psychosocial concerns.
The remaining 12 weeks in the program include sessions with the RD and CCPT. The diet prescription may be modified depending on lifestyle changes the participant has made. A new or revised meal plan and exercise plan will be provided. The nutritional goals are to build meal planning, portion control skills, and integrating the diet prescription into the participants' current dietary preferences. During this period of the program, the exercise program will be introduced, which is designed to fit the participant's lifestyle and meal plan. Through regular interactions through e-mail or phone and monthly in-person appointments between participants and RD and CCPT, meal and exercise plans will be adjusted based on progress, barriers, and feedback. During the monthly check-ins with the participant and RD, the following will be addressed: meal balance, nutrient balance promoting weight management and satiety, transitioning to self-planned diet, healthy eating strategies, meal planning, pre- and post- workout nutrition, balancing eating and hunger with activity, how to account for extras (snacks, desserts), weight maintenance planning, reviewing program action plan, managing plateaus, incorporating eating out, and relapse management. Each topic will be addressed according to the participants’ progress, barriers, and feedback. During the monthly check-ins with the participant and CCPT, the exercise will include cardio, resistance training, flexibility prescription (FITT (frequency, intensity, time and type of exercise) principle), weight monitoring and exercise goals.
After 17-weeks in the program, the participants have the option of entering a maintenance phase. During this phase, the participant will have two meetings per month with the RD and CCPT. This phase will aid in the progression from previous weeks to the maintenance phase by making the habits participants learned their new normal, learning how to develop their own meal and exercise plans, and supporting them to sustain their weight. For the purposes of the evaluation, the maintenance phase will not be included.
Outcome Measures
To evaluate the effectiveness, outcome and feasibility measures will be collected. Outcome measures will be taken prior to starting the program and at four months. For those who do not complete the program, all measures up until participant exit will be collected. Due to the personalized nature of the weight loss goals in this program, the percentage of participants meeting their weight loss goals within the timeline will be considered in the evaluation of the program’s effectiveness. The outcome measures are listed below.
Anthropometric Measurements and Body Composition. Anthropometric measurements, such as height and weight will be measured using a weighing scale stadiometer. Waist circumference will be measured three times with the average reported. Body composition will be measured using the InBody 570 (InBody USA, 13850 Cerritos Corporate Drive Cerritos, California, USA), a non-invasive 45 second test where the participant will stand on a device and hold the hand electrodes (13). The InBody 570 uses bioelectric impedance analysis (BIA) technology where safe low-level currents are sent through the participant’s body through the hand and foot electrodes. The impedance is then used to determine body composition, such as percentage of body fat, lean body mass, body fat mass, and basal metabolic rate (14). These measurements will be used to indicate the participant’s body composition, BMI and risks for other chronic diseases.
Cardiovascular Assessment. An oscillometric blood pressure monitor will be used to collect the systolic and diastolic blood pressure and heart rate. A cardiovascular risk assessment based on age, HDL-C levels, total cholesterol levels, systolic blood pressure, smoking status, and diabetes status will be reviewed to determine the participants 10-year risk of cardiovascular disease and identification of metabolic syndrome (8).
Clinical Chemistry. The following clinical data will be collected: total cholesterol, HDL-C, LDL-C, triglycerides, total cholesterol/HDL ratio and hemoglobin A1C. The lipid profile blood sample will be collected and processed by the Diagnostic Services of Manitoba. The results for the clinical data will be collected on eChart, which is an electronic database used to access key patient health information(15).
Physical Activity. The Ebbeling single stage treadmill walk test or the six-minute walking test will be used to assess aerobic capacity and endurance as estimated by measuring the participant's maximal oxygen uptake (VO2 max). During the Ebbeling single stage treadmill walk test, the participant will be required to walk at a steady pace on a treadmill (16). The six-minute walking test requires a 100-feet hallway and no exercise equipment, the distance the participant can quickly walk on a flat, hard surface in a period of six-minutes will be measured (17). For those unable to complete the Ebbeling single stage treadmill walk test, a six-minute walking test will be administered. Both tests are validated by the CSEP guidelines (18). Following the aerobic assessment, a strength assessment will be administered, such as a grip strength and push up test. During the push up test, the participant will be asked to perform as many push ups as they can with no time limit (18). To measure grip strength, the participant will be asked to hold a dynamometer and both dominant and non-dominant hands will be tested and recorded (18).
Nutrition. Questionnaires that will provided for the participants include mindful eating questionnaire, three-factor eating questionnaire, and three-day food recall. The three-factor eating questionnaire measures three components: cognitive restraint, uncontrolled eating, and emotional eating (19). Where the mindful eating questionnaire measures five components: disinhibition, awareness, external cues, emotional, and distraction (20). A three-day food recall will be filled out by the participant; this tool may be used to measure adherence to the meal plan. The three-factor eating questionnaire and the mindful eating questionnaire will be scored and interpreted, along with the three-day food recall, to guide the nutrition assessment done by the RD.
Behaviour Change and Health Screening Questionnaires. The following questionnaires will be administered to the participant: stages of change questionnaire, general self-efficacy scale, and the WI health screening questionnaire. The Stages of Change questionnaire (also known as, S-weight) contains five mutually exclusive responses corresponding to the five stages of change: pre-contemplation; contemplation; preparation; action; and maintenance (9). The general self-efficacy scale is a list of ten questions that assess behaviour-specific self-efficacy, social-cognitive constructs, well-being, health behaviours, and coping strategies(21). The WI Health Screening questionnaire will also be administered to the participant, which is based upon the Physical Activity Readiness Questionnaire by CSEP (18) and was reviewed by the Medical Director of the WI. It is used to determine any health risks associated with physical activity and if the participant will require a GXT test. In addition, to identify mild to severe depression and anxiety, respectively, the following are administered: Beck’s Depression Inventory and Beck Anxiety Inventory (10). Information, such as health and medical history, reason for joining, occupation, lifestyle and leisure, sleep patterns, energy levels, goal weight, previous attempts, weight gain triggers, stress levels, and overall wellness goals will be obtained from the participant via the initial assessment questionnaire created by the WLC team. The program evaluation will include the SF-36 quality of life questionnaire and the Pittsburgh sleep quality index questionnaire. The SF-36 quality of life questionnaire measures nine areas: physical functioning, role functioning (emotional), role functioning (physical), energy/fatigue, emotional well-being, social functioning, pain, general health, and health change (22). The Pittsburgh sleep quality index questionnaire measures the quality and pattern of sleep in adults, and includes seven components: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping meds, and daytime dysfunction (23).
Statistical Analysis
Statistical analysis will be performed using R Studio (R Studio, Boston, MA, USA) (24). The effects of participation in the weight loss program on the captured outcomes will be analysed by R generalized linear model (GLM) function using a pre- post- design. The primary outcomes and other binary outcomes, such as personal goal weight (if achieved a loss of over 5% initial body weight) and program compliance will be measured by logistic regression. Secondary outcomes, such as changes in body weight, waist circumference, blood pressure, clinical chemistry, quality of life, and sleep will be analysed through a paired t-test and McNemar’s chi-squared test with continuity correction. Factors such as sex, baseline BMI, and age may be included in the model as fixed factors or covariates. Feasibility outcomes will also be measured, such as attendance, intervention adherence, and participant feedback. This study is an evaluation of a clinically managed weight loss program that is currently offered, it has only one group and does not include randomization.