Motivation and emotion/Book/2016/Group motivation and weight loss

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Group motivation and weight loss:
How can undertaking diet and exercise goals in peer groups motivate people to lose weight?
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Every once in awhile you get encouragement, or you get something that isn't competitive or guilt-inducing from your peers, and it just turns a little light on - Julie Klausner

The World Health Organisation (2015) reported that as of 2014, 39% of the world's adult population and approximately 10% of the world's child population were overweight or obese, with this figure having doubled since 2005. Being overweight or obese is most often a result of poor health behaviours such as physical inactivity and excessive food consumption, and as a person's body fat increases so do their predicted rates of non-communicable diseases, such as Type 2 diabetes and cardiovascular disease (Schroeder, 2007). It has been estimated that nearly three-quarters of public health care costs can be attributed to treatment of such chronic diseases (Hilbert, 2016). Consequently, obesity is regarded as one of the most serious health concerns of the 21st Century (DiBaise & Foxx-Orenstein, 2013). Fortunately, body weight can usually be managed by making ongoing alterations to one's lifestyle, particularly through changes to diet and exercise habits (Catenacci & Wyatt, 2007). However, for some people this is easier said than done.

One must have strong self-regulation and motivation to successfully make diet and exercise improvements to lose weight (Catenacci & Wyatt, 2007). Goal setting is a strategy that is frequently used to initiate changes to one's lifestyle, with many people having a specific weight loss goal in mind that they would like to achieve (Teixeira, Silva, Mata, Palmeira, & Markland, 2012). Maintaining weight loss goals in both the short and long-term can be extremely difficult, and many people find themselves losing motivation and regressing back towards their old lifestyle habits (Ward & Mann, 2000). So, how does one maintain the motivation needed to accomplish their weight loss goals?

An abundance of research has focused on answering this question by examining practical methods that will successfully help people maintain their motivation to lose weight, and a potential solution may involve goal setting in peers groups. A meta-analysis conducted by Burke, Carron, Eys, Ntoumanis and Estabrooks (2006) identified the importance of social support in motivating people to initiate and maintain health promoting behaviours such as diet and exercise, which in turn can help people to lose weight. The following chapter will focus on motivational and goal setting theories that have been applied to investigate physical activity and dieting behaviours in both individual and group settings. These theories will then be utilised to determine how peer-groups may influence diet and exercise behaviours, and their overall effectiveness on helping individuals accomplish their weight loss goals.

Underlying theories and their applications[edit]

The following psychological theories have been examined due to their inclusion of both motivational and goal setting factors, as well as the extensive research that has been conducted utilising these theories to alter health behaviours. Particular focus has been given to studies that have applied these theories to research peer influences on diet, physical activity and weight loss.

Self-determination theory[edit]

Self-determination theory was initially developed by Deci and Ryan (2000), and focuses on both environmental and social factors that can influence people's motivation and psychological needs for optimal growth and development. The theory has two main motivational constructs that influence people's behaviour - intrinsic and extrinsic motivation.

Extrinsic motivation refers to performing a behaviour for the purpose of achieving an external outcome, such as a reward or praise, and can be either facilitated or hindered by social support (Deci & Ryan, 2000). Intrinsic motivation refers to an individual's inner desire to search for new experiences and challenges that provide enjoyment and satisfaction (Deci & Ryan, 2000). SDT proposes that intrinsic motivation is facilitated by three innate psychological needs - autonomy, competence and relatedness.

Self-determination thoery
Figure 1. The three innate psychological needs of self-determination theory


Also called self-determination, autonomy refers to the psychological need to initiate and regulate one's own behaviour (Deci & Ryan, 2000). When a person's interests, preferences and wants guide their decision making process to engage in a behaviour, they are fulfilling their need for autonomy (Miller, Deci & Ryan, 1988). Three underlying factors can influence a person's experience of autonomy: internal perceived locus of causality, volition and perceived choice over one's actions (Deci, 1971). If any of these factors negatively interfere with a person's perceived sense of autonomy, motivation may be hindered (Deci, 1971). A person's need for autonomy can be fulfilled by receiving support from peers, which in turn promotes greater psychological growth and need satisfaction (Deci & Ryan, 2000).


Competence refers to the desire to achieve mastery and control over one's experiences within an environment, and motivates people to seek out and persist with challenges until they have been successfully mastered (Deci & Ryan, 2000). A study by Harter (1978) found that task difficulty had an effect on competence needs, with children remaining motivated to complete challenges that were of moderate difficulty. Challenges that were too easy or too difficult resulted in decreased motivation (Harter, 1978). Feedback is an important component of the need for competence, as it allows for the individual to determine how well they have mastered a task (Deci & Ryan, 2000). Feedback can be gained by making comparison of one's own performance against another's performance of the same or similar task. Feedback in the form of verbal praise from others can also increase perceived competence, however it is most effective in the form of mentoring, as it can help to enhance one's skills (Deci & Ryan, 2000).


Relatedness is the psychological need to establish relationships that give the individual a sense of an emotional connection with another person (Deci & Ryan, 2000). The need for relatedness is not satisfied through fleeting social interactions, but through interactions that establish social bonds that are called communal relationships (Carvallo & Gabriel, 2006). Communal relationships are caring, accepting and valuing, and most often exist between family members, friends and romantic partners (Deci & Ryan, 2000). The more the need for relatedness is fulfilled, the greater the likelihood is of an individual feeling motivated to engage in a behaviour (Deci & Ryan, 2000).

SDT provides an insightful hypothesis as to why undertaking diet and exercise goals in groups may produce more effective weight loss outcomes, as evidence suggests that people are more likely to initiate and maintain health promoting behaviours when their psychological needs are met. A meta-analysis conducted by Rhodes, Fiala, and Conner (2009) reported that intrinsic motivation had a significant positive correlation with participation in physical activity behaviours, and a subsequent study by Silva et al. (2009) determined that using SDT principles to promote physical activity was also an effective weight control method[Provide more detail].

SDT principles have also been used to motivate group exercise and dieting behaviours. Perceived peer support during exercise has been associated with a significant increase in intrinsic motivation, most likely due to the ongoing social support and feedback that the peers provided to increase the three innate psychologcial needs of SDT (Murcia, de San Román, Galindo, Alonso, & González-Cutre, 2008).

Extrinsic motivation has also been found to be increased due to the ongoing peer feedback and praise that commonly takes place during group exercise participation (Jõesaar, Hein, & Hagger, 2012). A study by Schösler, de Boer, and Boersema (2014) found that intrinsic motivation had a large impact on participants' diet, particularly when the dietary changes were made collectively as a group. It was hypothesised that due to their shared feelings of solidarity, each group members' need for relatedness was satisfied, consequently motivating participants to continue to consume a healthier, more sustainable diet (Schösler et al., 2014). Overall, many findings suggest that when psychological needs are satisfied, more significant participation in physical activity and dieting behaviours occur, which are associated with weight loss goals being achieved (Silva et al., 2009).

Social cognitive theory[edit]

Figure 2. Dancers modelling the behaviour of their instructor

Albert Bandura's 1986 Social Cognitive Theory (SCT) provides a complex framework for understanding, predicting and changing human behaviour. In short, SCT proposes that people have control over their own actions, and can learn new behaviours by observing others through social interactions and experiences, a process known as modelling (Bandura, 1986). The concept of modelling is one of the key features of the theory, and has been demonstrated to be exceptionally effective for learning when the model is a person highly regarded by the observer, such as a friend, coach or mentor (Bandura, 1986). The theory differentiates itself from other learning, cognitive and behavioural theories through its proposal of reciprocal determinism, which states that social/environmental, personal and behavioural factors have dynamic interactions with one another (Bandura, 1997). Schunk and Usher (2012) examined the underlying cognitive processes of SCT that can serve to motivate behavioural change, and found four crucial mediating factors, outlined below.

  • Self efficacy - a judgement of one's ability to successfully perform a behaviour, and can be influenced by others either via forms of verbal persuasion, vicarious experiences or modelling. When self-efficacy increases, so does outcome expectations, as people will place more effort and persistence into achieving their goals.
  • Social support - the perceived support one has to perform a behaviour. The greater the social support, the greater one's self-efficacy.
  • Outcome expectations - the social, physical and self-evaluative beliefs one has about the effects of a behaviour - dependent on self-efficacy.
  • Self-regulation - an ongoing behavioural process which involves goal setting, planning and motivating oneself to engage in a new behaviour.

SCT has been a central theory surrounding many health behaviour studies that utilise group settings (McAuley, Blissmer, Katula, Duncan, & Mihalko, 2000). Studies have shown that SCT can be applied to increase participation in physical activity behaviours, as peers provide opportunities for observational learning by modelling physical exercises, which can consequently lead to increases a person's self-efficacy (McAuley et al., 2000). SCT has also been applied to examine peer influence on dieting behaviours, with a study conducted by Anderson, Winett, and Wojcik (2007) finding that social support was a crucial factor that was associated with participant's{{g]] healthier food purchases and intake. It was hypothesised that when participants were socially supported by their peers regarding their diet, they felt increases in self-efficacy, which in turn increased outcome expectations and self regulation, enabling the person to resist tempting, unhealthy foods and instead opt for healthier food choices (Anderson et al., 2007).

Goal setting theory[edit]

Locke and Latham's goal setting theory attempts to explain how consciously setting goals can motivate people and regulate task performance. In particular, the theory proposes that hard, specific goals are associated with higher levels of performance than easy, generalised goals (Locke & Latham, 2006). The hypothesis behind this association is that harder and more specific goals facilitate motivation by requiring one to attain more in order to be satisfied than do low, or easy, goals (Locke & Latham, 2006). Furthermore, setting goals may potentially influence how performance on tasks is affected by external factors, such as feedback and praise (Locke & Latham, 2006).

Goal setting has been found to be an particularly effective way to enhance performance in physical activity settings, and is often used as a psychological intervention technique for training athletes (Burton, Pickering, Weinberg, Yukelson, & Weigand, 2010). A study by Weinberg et al. (2000) found that setting goals in both the short and long-term was of importance for athletes to maintain high levels of motivation and performance over extended periods of time. It was hypothesised that short-term goals allowed for the athletes to gain feedback about their performance, which consequently allowed them to assess their progress towards their long-term goal (Weinberg et al., 2000). In turn, the long-term goal provided focus for short-term performance (Weinberg et al., 2000). A study by Nothwehr and Yang (2006) investigated how frequent, short-term goal setting affected weight loss outcomes, and found that individuals who set specific short-term goals regarding diet and exercise habits were more likely to participate in their target behaviours, as opposed to individuals who just focused on more generalised weight loss goals. However, it was undetermined whether this goal setting approach helped to maintain weight loss goals in the long-term (Nothwehr & Yang, 2006).

Group performance has also been shown to be enhanced by goal setting. A meta-analysis conducted by Kleingeld, van Mierlo, and Arends (2011) found that group goals that were of moderate difficulty and specificity could significantly enhance overall group performance on tasks. The meta-analysis also found that participants' individual goals could also contribute towards group performance, as long as the individual goals were "groupcentric", not egocentric (Kleingeld et al., 2011). This has been demonstrated in a physical activity setting, with a study by Burke, Shapcott, Carron, Bradshaw, and Estabrooks (2010) having identified a positive relationship between combined individual and group goal setting increasing the overall physical activity levels of participants. There is however, a caveat to group goal setting. A phenomenon called social loafing can occur when groups goals are made without individual goals as well. Performance is reduced when team members exert less individual effort due to feeling that the other group members can make up for their reduced effort (Karau & Hart, 1998).

Achievement goal theory[edit]

Achievement goal theory (AGT) focuses on understanding the role and significance of goal-directed behaviours by determining how people define their success, and how they judge their performance (Ames & Archer, 1988). AGT proposes that people are motivated to achieve their own set-standards of excellence, and that their behaviour can be explained by which achievement goals they choose to adopt (Elliot & Dweck, 1988). Achievement goals are differentiated from regular goals, as instead of simply representing a desired outcome, they attempt to explain why a person wants to achieve them (Elliot & Dweck, 1988). There are two main types of achievement goals - performance goals and mastery goals. Mastery goals and performance goals both have different implications for motivation and an individual's judgement of their perceived success (Ames & Archer, 1988).

Performance goals[edit]

When a person adopts performance goals they seek to perform better than others by proving their abilities to a high, self-set standard, and succeeding with little noticeable effort (Elliot & Dweck, 1988). Adoption of performance goals has been associated with negative, unproductive methods of thinking, feeling and behaving that result in lower and less persistent task performance (Spence & Helmrich, 1983).

Mastery goals[edit]

When mastery goals are adopted people will strive to achieve greater competence, make progress, improve the self and overcome difficulties with effort and persistence (Elliot & Dweck, 1988). People will perceive that they have succeeded when they have given a task maximum effort, noticed improvement and enjoyed the task process (Spence & Helmrich, 1983). Adoption of mastery goals has been found to be associated with productive ways of thinking, feeling and behaving, and has also been found to relate to SDT's intrinsic motivation's needs for autonomy, competence and relatedness (Ames & Archer, 1988). Studies have also found that people who adopt mastery goals are more likely to persist longer and perform better at tasks, even when they face setbacks (Elliot & Dweck, 1988; Spence & Helmrich, 1983).

AGT has been applied to predict physical activity intention behaviours. A study by Standage, Duda, and Ntoumanis (2003) found adoption of mastery goals was a significant predictor of students participation in physical activity behaviours. The study also found that constructs from both AGT and SDT interacted, as autonomy, competence and relatedness needs were found to have a positive association with mastery goal adoption (Standage et al., 2003). Furthermore, a study conducted by Hagger, Hein, and Chatzisarantis (2011) found that people who adopted mastery goals also displayed higher levels of competence, and were more likely to go to the gym regularly. These findings help to support the notion initially made by Ames and Archer (1988), that a relationship exists between SDT and AGT.

AGT can also be applied to predict dieting behaviours. Adoption of performance goals has been found to be associated with disordered eating habits in female gymnasts and dancers, perhaps due to increased perceptions of peer pressure and the emphasis placed on performance goal approaches within the sports (de Bruin, Bakker, & Oudejans, 2009). Fortunately, the study also found that when gymnasts and dancers instead focused on mastery goals, they perceived less peer pressure and were protected from disordered eating behaviours (de Bruin et al., 2009). A subsequent study by Woelders, Larsen, Scholte, Cillessen, and Engels (2010) emphasised the importance of setting diet goals with caution, as both young men and women were found to be particularly likely to adopt performance goal approaches to dieting, and were at risk of developing body image concerns that could be compounded by peer influences.

Group motivation and weight loss[edit]

The psychological theories discussed provide a strong theoretical framework to support the notion that peer support may be able to help motivate people to initiate and maintain diet and exercise goals in order to lose weight. The following section will utilise these theories to provide a peer-motivated strategy that could help people to lose weight.

Bringing it all together[edit]

 “Weight loss doesn't begin in the gym with a dumb bell; it starts in your head with a decision.”

—Toni Sorenson

While peers can help to provide the ongoing motivation that is required to maintain healthier diet and exercise behaviours, the initial motivational foundations must be built by the individual, as it is they who must make the pivotal decision to lose weight (Teixeira et al., 2012). Once this step has been made, the motivation to lose weight begins to exist and goal setting can begin. In particular, people should start by aiming to set realistic, but challenging short term goals that are concerned with diet and exercise behaviours, not just generalised "exercise and eat better" goals (Nothwehr & Yang, 2006). Setting a specific long-term weight loss goal is also recommended, as this can be easily measured and be a source of further motivation (Burton & Weiss, 2008). Adoption of a mastery goal approach is recommended, as this is likely to be more predictive of physical activity and dieting effort, improvement and maintenance than a performance-based approach to these goals (Hagger et al., 2011).

For example:

  • Short-term goals: exercise for thirty minutes four days per week, eat daily recommended amount of vegetables
  • Long-term goal: lose five kilos.

By setting both short and long-term goals, people are more likely to see weight loss results by having higher levels of persistence with participating in physical activities (Hagger et al., 2011), and are also less likely to succumb to tempting unhealthy food choices (Nothwehr & Yang, 2006). Once both individual short and long-term goals have been established, actual participation in the goal behaviours can begin, and it is at this point that peers can start to become a significant influence on weight loss motivation.

Figure 3. Gym group classes can help people remain motivated to stay active.

There are a wealth of situations which provide people with the opportunity to participate in physical activities in peer settings, such as gym group classes, organised team sports, and unstructured exercise with friends (Spink, Ulvick, Crozier, & Wilson, 2014). These situations provide a good opportunity to establish group goals - be it to exercise together on a set schedule, or to win the team's sports competition. These kinds of group goals increase the likelihood that the individual will keep up with participating in physical activity behaviours and, over time, lose weight (Silva et al., 2009).

According to SCT, peers participating in the same or similar physical activity can provide opportunities to maintain motivation through social support, particularly if the individual is lacking in self-efficacy and self-regulation (McAuley et al., 2000). Various forms of observational learning can take place, and performance feedback can also be given to the individual, be it through verbal means, or by modelling desired behaviours. For example, if a person is unsure about how to perform a weightlifting manoeuvre at the gym, a peer can first demonstrate this behaviour, then provide feedback about the individual's own attempts at the lift. This in turn can allow for the individual to gain self-efficacy which, being linked to SDT, can lead the individual to feel more motivated to continue to participate in the exercise due to their autonomy, competence and relatedness needs being fulfilled.

Participating in peer group activities can also be a good opportunity to establish group diet goals. Perhaps the group could try adhering to a new, healthier diet (Schösler et al., 2014), or agreeing that each person is only allowed to get take-away once per week. Even grocery shopping together could be tried, as the peers can provide the support needed to stick to the diet goals (Anderson et al., 2007). However, these diet goals should be established with careful consideration, as they can potentially lead to disordered eating habits if a peer has a performance goal based approach (Woelders et al., 2010).

Throughout this process, peers can increase the individual's extrinsic motivation by supporting or congratulating them about their diet and exercise goal progress, or even their performance with regard to the team goals or task performance (Catenacci & Wyatt, 2007). This ongoing support can be a crucial factor in getting people to maintain focus on their short and long-term goals, particularly if they face any set-backs. Team goals also provide the individual with another source of motivation, as they will be reluctant to let the team down.

Eventually, through persistence, effort, and ongoing social support, short-term diet and exercise goals can be accomplished, perhaps with an additional team goal being met as well. Over time, these goals will contribute to the accomplishment of the long-term weight loss goal, at which point reassessment of new goals can begin (Teixeira et al., 2012).

Principles of group motivation and weight loss - a quick review[edit]

Click the arrows to review the basic steps to group motivation and weight loss.

Can peers help motivate me to lose weight?[edit]


Do you want to lose weight?



Do you like setting personal goals for the near and distant future?



When you do something, what concerns you most?

Am I trying my hardest?
What other people think of me.


Do you like associating with other people?



Do you care about doing your best for the sake of other people?



Do you struggle to maintain motivation on your own?


If you answered yes to all of these questions, then undertaking diet and exercise goals in groups may help motivate you to lose weight!


The importance of undertaking healthy diet and exercise behaviours is becoming more prevalent with the world's increasing rates of overweight and obese populations. Losing weight is difficult, and many people find themselves lacking the motivation required to meet their weight loss goals. However, psychological theories provide a basis for understanding how setting goals can help to maintain motivation, which in turn can lead to increased participation in healthier diets and exercise behaviours. Research utilising these theories has also indicated the importance of social support for maintaining the motivation to accomplish diet and weight loss goals.

After an individual has decided to lose weight and established their personal diet and exercise goals, participation in peer activities can help to foster ongoing motivation. Peers provide people with opportunities to learn and increase their self-efficacy, which can furthermore allow people to fulfil their innate psychological needs and become intrinsically motivated. Peers also increase extrinsic motivation by providing people with continuous feedback on their short and long-term goals, helping people to maintain their focus to reach their desired, long-term weight loss outcome. However, group motivation may not be suited to everyone, and one should consider their personal needs and goals before undertaking it as a weight loss strategy.

See also[edit]


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Bandura, A. (1986). Social foundations of thought and action. Englewood Cliffs, N.J.: Prentice-Hall.

Burke, S. M., Carron, A. V., Eys, M. A., Ntoumanis, N., & Estabrooks, P. A. (2006). Groups versus individual approach? A meta-analysis of the effectiveness of interventions to promote physical activity. Sport and Exercise Psychology Review, 2, 19-35.

Burke, S., Shapcott, K., Carron, A., Bradshaw, M., & Estabrooks, P. (2010). Group goal setting and group performance in a physical activity context. International Journal Of Sport And Exercise Psychology, 8(3), 245-261.

Carvallo, M. (2006). No Man Is an Island: The Need to Belong and Dismissing Avoidant Attachment Style. Personality And Social Psychology Bulletin, 32(5), 697-709.

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DiBaise, J. & Foxx-Orenstein, A. (2013). Role of the gastroenterologist in managing obesity. Expert Review Of Gastroenterology & Hepatology7(5), 439- 451.

Elliot, E., & Dweck, C. (1988) Goals: An approach to motivation and achievement. Journal of Personality and Social Psychology, 73 , 171-185

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