Recent measurements of height and weight show that more than one-four of Canadians
Adults who have a measured Body Mass Index (BMI) of 30 or higher are considered obese.
Public Health Agency of Canada, 2011; kg/m2. Measured information is included.
BMI levels in the overweight range (between 25 and 29 kg/m2), this number
grew in 2008, reaching 62.10% of Canadians (PHAC, 2011). Obesity is associated with
several ongoing medical issues, such as hypertension, coronary artery disease,
high cholesterol, type 2 diabetes, joint discomfort, stroke, and numerous cancer kinds
In 2006, (Blissmer, Riebe, Dye, Ruggiero, Greene, & Caldwell), both direct and indirect expenses
Depending on estimates, between $4.6 billion and 7.1 billion (CAD$) each year are attributable to obesity.
A 2008 estimate (PHAC, 2011). The rising frequency of overweight people overall
coupled with obesity, the heightened chance of developing chronic medical disorders,
associated costs emphasize the significance of public health programs that focus on both
Canada's programs for preventing and treating obesity and overweight (PHAC, 2011).
What Physical Activity Does
The well-known risk factors for maintaining a healthy body weight include uncontrollable elements including metabolic sensitivity, age, and gender.
& Haskell, 2007) as well as manageable elements like energy intake and expenditure (Hill, Wyatt, & Peters, 2012). Numerous studies have demonstrated that increasing physical activity has a positive impact on energy expenditure, which makes it useful for preventing weight gain and lowering body weight in overweight and obese populations.
weight control success (Hill et al., 2012; Jakicic, 2009; Shaw, Gennat, O'Rourke, & Del Mar, 2006).
Any bodily movement that raises overall energy expenditure above resting values is referred to as physical activity (PA) (Bouchard et al., 2007). The various domains that make up total daily physical activity include occupational activity, commuting, leisure time physical activity (LTPA; such as exercise, sport), and household chores (van Tuyckom & Scheerder, 2010). Lifestyle-embedded activities, such as incidental walking, household chores, or personal care, as well as commuting or active transportation, are not included in LTPA (Bryan & Katzmarzyk, 2009). LTPA has been identified as one of the best predictors of long-term weight loss due to its impact on energy expenditure and is frequently prescribed as a way of weight regulation for both overweight and obese people (Jakicic, Marcus, Gallagher, Napolitano, & Lang, 2003). In both Canadian men and women, higher levels of obesity are linked to lower levels of LTPA (PHAC, 2011). The Canadian PA guidelines advise Canadians to engage in 150 minutes of MVPA (moderate to vigorous intensity PA), which can be broken up into sessions of at least 10 minutes, each week in order to reap the health advantages (Colley et al., 2011). According to the CSEP (2011), MVPA for adults is defined as operating at a minimum intensity of three times that of rest or at a minimum of three metabolic equivalents (METS; WHO, 2013).
Self-report data from the Canadian Community Health Survey reveals that, despite public health recommendations, just over half (53.80%) of Canadians over the age of 12 reported meeting physical activity recommendations in 2011. (Statistics Canada, 2012). When measuring PA with accelerometers, Colley et al(2011) .' s research revealed that the proportion of Canadian adults (>20 years) meeting the recommended
Norms dropped to 15.40%. However, it falls short of the higher doses of MVPA (about 300 minutes per week) that appear to be necessary to affect weight loss. It is crucial to highlight that the recommended accumulation of 150 minutes of MVPA per week is congruent with health benefits (CSEP, 2011). (Catenacci & Wyatt, 2007; Jakicic, 2009; Jeffery, Wing, Sherwood, & Tate, 2003). No of the method of assessment (e.g., accelerometry vs. self-report) or the classification criteria, it is clear that Canadians do not engage in enough PA to benefit their health or control their weight.
Interventions in Lifestyle to Promote Weight Loss
Multiple etiologies contribute to the complex medical condition of obesity (Sharma, 2007). Energy intake over expenditure leads to excess body fat, which is influenced by genetic, metabolic, biochemical, cultural, and psychosocial variables (Lang & Froelicher, 2006). Therefore, methods for affecting weight loss can and do differ substantially (Sharma, 2007). As a result, there is a lot of variation in the effectiveness and design of weight loss programs, according to meta-analyses (Michie, Abraham, Whittington, McAteer, & Gupta, 2009). Although there is some variance, therapies typically employ tactics to change the two lifestyle behaviors that have been demonstrated to have the biggest influence, LTPA and food consumption (Lang & Froelicher, 2006; Sharma, 2007). 1
However, the outcomes are frequently modest (i.e., less than 5kg) (Shaw et al., 2006) or less than 3% of original body weight. Weight loss has been demonstrated to occur with PA-only therapies (Hill et al., 2012). (Jakicic, 2009). Despite the fact that the relationship between increased PA and weight control appears to be well established (Catenacci & Wyatt, 2007; Chaput et al., 2011; Donnelly et al., 2009), it has been noted that there are conflicting results regarding the effectiveness of LTPA in the cause and maintenance of weight loss (Cook & Schoeller, 2011). Energy consumption per bout for aerobic exercise conducted in the same amounts has
been demonstrated to affect weight gain in some people and weight loss in others (Chaput & Sharma, 2011). For instance, King et al. (2009) noted that in a 12 week supervised aerobic exercise intervention, almost half of the participants were classified as non-responders to PA because they either lost very little weight (on average 0.9kg) or gained weight during the intervention. The lack of response (i.e., weight loss) attributed to LTPA in the short term has not been directly linked to the PA itself but rather to either increased caloric intake or decreased non-exercise activity (Cook & Schoeller, 2011).
Increased LTPA is strongly advised for all Canadians since physical inactivity is the factor most strongly connected with obesity at the population level (PHAC, 2011). But given the evidence for and against LTPA's role in weight loss (Cook & Schoeller, 2011), more research is necessary to understand the value of interventions for promoting weight loss and to assess their effectiveness. Furthermore, the ambiguous nature of LTPA's participation in weight loss may be attributed to variations among particular elements used in behavioral interventions (Sharma, 2007). In light of this, researchers have worked to clarify the behavioral intervention elements that are most strongly associated with successful weight loss results.
Intervention Period. Interventions typically last between 8 weeks to 2 years, with those lasting at least 6 months providing the best results in terms of weight loss (Sharma, 2007). However, studies on people who are overweight or obese have also indicated that shorter interventions (i.e., 12 weeks) can be successful at helping them lose weight (Hays et al., 2004; Kraemer et al., 1997; Saris, Hul, & Baak, 2003; van Aggel-Leijssen et al., 2002). More recently, a 12 week eight-arm randomized controlled trial (RCT) weight reduction intervention comparing a number of commercial weight loss programs was carried out by Jolly et al.
programs for primary care and a comparison group. They came to the conclusion that in an obese population, a 12-week intervention can result in clinically meaningful weight loss (on average, 1.37 - 4.43 kg per person) that can be maintained for a year.
The Exercise Guidelines. The length and intensity of PA prescribed during the intervention is another factor that varies among weight loss interventions. According to Catennaci and Wyatt (2007), the length of time required for an intervention can range from 60 minutes to 240 minutes each week, and its intensity can be anything from light (such as walking) to vigorous (i.e., jogging or resistance training; Blair, LaMonte, & Nichaman, 2004). As was already mentioned, the current recommendation of 150 minutes of MVPA per week to improve health (Colley et al., 2011) does not appear to be sufficient to cause weight loss or weight regain after weight loss (Catenacci & Wyatt, 2007; Jakicic, 2009; Jeffery et al., 2003; Saris et al., 2003). It's important to remember that the additional MVPA minutes that seem to be necessary for weight loss are independent of other lifestyle behaviors (such as changes in energy intake) that affect weight loss collectively (Jakicic, 2009), suggesting that a combination approach to weight loss may result in fewer MVPA minutes being required.
Despite research suggesting that increasing PA can help people lose weight (Ohkawara, Tanaka, Miyachi, Ishikawa-Takata, & Tabata, 2007; Shaw et al., 2006; Silva et al., 2011), treatments that just use PA alone report an average weight loss of 0.6-3.0 kg when compared to controls (Catenacci & Wyatt, 2007). Catenacci and Wyatt's (2007) findings that interventions that required more PA (i.e., 60–90 minutes per day) had higher success rates led them to draw the conclusion that more exercise is required to promote weight loss than is typically recommended in studies, which could be one explanation for this small effect. In light of this, weight loss interventions
The MVPA may need to be practiced at levels far greater than those recommended for health (150 minutes per week) or those frequently found in the literature in order to promote changes in energy expenditure alone (60-180 minutes per week; Catennaci & Wyatt, 2007; Stubbs & Lavin, 2013).
The level of PA prescribed also had a significant impact on body weight, with more vigorous intensity PA leading to more weight reduction than that participated in at a moderate or low intensity, according to a Cochrane analysis on activity for overweight or obesity (Shaw et al., 2006). Exercise at or above 60% of your maximum heart rate or your maximum oxygen consumption (VO2 max) was deemed strenuous intensity for this review (Shaw et al., 2006). They use MVPA, defined as 64–76% of maximal heart rate, as their definition of vigorous intensity, which is consistent with the moderate range advised by Canada's PA guidelines and used in the current study (Warburton, Katzmarzyk, Rhodes, & Shephard, 2007). The inconsistent definition of intensity among research may possibly be a factor in the inconsistent findings regarding PA's efficacy for weight loss (Boutcher & Dunn, 2009).
Dietary Recommendation. The behavioral approach to obesity's nutrition component can vary depending on the intervention (Hankey, 2010). Diets with less calories and less fat are most frequently utilized as weight loss therapies (Shaw et al., 2006). In a successful RCT, Silva et al. (2010) outlined specific nutritional strategies for their female participants to follow over the course of the one-year intervention. These strategies included reducing daily caloric intake by 300–400 kcal, eating breakfast, eating more frequently throughout the day, reducing dietary fat, increasing consumption of fruits and vegetables, and reducing consumption of highly pro-inflammatory foods.
2010). These dietary recommendations are comparable to those made by Health Canada in Canada's Food Guide to enhance Canadians' health (Bush & Kirkpatrick, 2003).
Weight loss is not a behavior in and of itself, but rather the result of adding or potentially removing many other behaviors. The general consensus is that when compared to "no treatment" controls or exercise-only interventions, interventions that target both PA and dietary behaviors result in greater weight loss (Sharma, 2007;; Shaw et al., 2006). Michie et al. (2009) found a small to moderate pooled effect size of 0.31 for weight loss programs utilizing increased PA and healthy eating based on the findings of a recent meta-analysis. Shaw et al. (2006) came to the conclusion in their review that diet-only therapies seemed to be more effective for weight loss than PA-only interventions. However, support for the use of exercise as a weight-loss intervention was found, particularly when it was paired with dietary modification (Shaw et al., 2006).
Support for Participants The quantity and kind of assistance that each participant receives throughout the intervention is another factor that contributes to variation in study design. One-on-one counseling was shown to be more effective in behavioral treatments for treating and preventing adult obesity than group sessions, according to an evaluation of those therapies (Sharma, 2007). The overall impact of delivery method is still unclear at this time, although more recent study suggests that "mixed-modal" delivery (a combination of one-on-one and group sessions) may be more beneficial for weight loss up to 6 months (Greaves et al., 2011). There are additional differences when one-on-one counseling is delivered in person as opposed to online, with larger effect sizes showing up when support is provided in person as opposed to online (Conn, Hafdahl & Mehr, 2011).