The Impact of Portion Plates for Weight Loss on Cardiac Rehabilitation Patients

In Canada, 6.8 million adults are overweight and an additional 4.5 million are obese, which translates to about 58.3% of Canadian adults being overweight or obese. The overall cost of obesity in British Columbia (2006) is estimated to be $563 million dollars. An increase in food portion sizes and sedentary lifestyle of Canadians has contributed to the imbalance in caloric intake and usage. Obesity is the leading risk factor for many chronic diseases and has been linked directly to an increased incidence of heart disease and hypertension.

Cardiac Rehabilitation (CR) Phase I involves the rehabilitation of patients with cardiac disease in an outpatient setting at the Richmond Hospital. It is an 8-week interdisciplinary program involving exercise, group education, and individual counselling. Currently, patients are referred by a cardiologist to the CR program and have parameters like their blood pressure and waist circumference measured at the first and final visits. Over the past year, the average change in blood pressure from the first to last day (after 8 weeks) was a reduction of 12.2 systolic blood pressure and 3.1 diastolic blood pressure. The average waist circumference changed by 0.88 cm. Patients are offered an optional individual visit with the dietitian and are required to attend a weekly nutrition education class.

Weight Loss with Portion Plates Portion sizes are essential in determining the amount of calories consumed at meal times. When larger portions are consumed, there is a greater amount of calories ingested. The Canadian Community Health Survey (2004) found that the average adult consumed about 2732 kilocalories daily, which is increased from the average of 2356 kilocalories in 1991.

One randomized controlled study looked at the impact of a portion control tool (portion plate) on the weight changes in diabetic patients and found a significantly greater weight loss in patients using the tool versus the control group. No other studies were found that measured the efficacy of these tools in cardiac patients.

Hypertension and Weight Reduction Body mass index (BMI) is a common tool used to compare height and weight, that is calculated by weight (kg) divided by height squared (m²). A person with an acceptable body weight has a BMI of 18.5-24.9 kg/ m². Obesity is defined as a BMI of 30 kg/ m². Increased body weight or a high BMI is a risk factor for hypertension. A reduction in BMI through non-pharmacological methods like caloric reduction and physical activity has significantly improved cardiac risk factors in some studies.