A Comparison of Three Intervention Models for Successful Weight Loss Maintenance facilitated by Gina Hage

Journal Club Summary

A Comparison of Three Intervention Models for Successful Weight Loss Maintenance

9 April 2014

Facilitated by Gina Hage

Background

Obesity prevalence has doubled worldwide since 1980. In 2011-12, 62.8% of Australian adults were classified as overweight or obese and prevalence is increasing at a rate of 0.3-0.8% per year. Problems associated with obesity include increased morbidity and mortality due to comorbidities as well as mental health problems (depression, anxiety, and quality of life). The economic burden of obesity in Australia was estimated to be $56.6 billion (2010)

There are many barriers to healthy eating and weight maintenance: genetic, psychological, biochemical, environment, social and economic. Current interventions to combat obesity include lifestyle changes (diet & exercise, psychological and behavioural therapy), pharmacological interventions and surgery. Regardless of the type of intervention, 40 % of weight loss is often regained over the first year and the rest in the following three years. Determinants of weight regain include: lack of knowledge, intention-behaviour gap, automaticity, lack of motivation, habits and ego depletion.

Habitual behaviour is triggered automatically without much deliberation and thought and therefore overrides good intentions. Automaticity operates outside of awareness; it is unconscious and difficult to control. We can exert a certain amount of self-control but at some point experience ego-depletion and fall back into old habits. The more habitual a person is, the higher their BMI (Pine, 2014). Therefore, interventions aiming to establish long-term behavioural changes might lead to successful and sustained weight loss.

Project presented

Gina Hage, a Dietitian/Nutritionist and PhD candidate at Bond University, presented her PhD project during this journal club. Gina plans a 3-armed randomised controlled trial comparing 3 intervention models for successful weight loss maintenance:

1)      Forming new habits (10 Top Tips): habit formation through daily repetition (8 weeks). This intervention focuses on lifestyle changes to take in fewer calories through food and burn more calories through activity (P. Lally, Chipperfield, & Wardle, 2008). http://www.cancerresearchuk.org/cancer-info/healthyliving/obesityandweight/tentoptips/ten-top-tips-weight-loss-tips-based-on-scientific-evidence

2)      Disturbing automaticity (Do Something Different): increase behavioural flexibility (6-8 weeks).

This behavioural programme focuses on breaking normal routines in simple ways, by doing something new or different every day for a period of time, e.g. taking a different route to work, or not watching TV for a day (Fletcher, Hanson, Page, & Pine, 2011).

3)      Usual care (Dietitian Counselling – diet & exercise): personal coaching to build intention-behaviour, based on information deficit model (10 weeks).

The study involves two interventions aiming to break habits. As it takes on average 66 days (range 18-254 days) to break a habit (Phillippa Lally, van Jaarsveld, Potts, & Wardle, 2010), the primary outcome measure of the study is weight loss success (5-10% of body weight) maintained over 12 months. Previous studies stopped follow-up at 6 months.

Discussion

It was suggested to look at what is special about people that maintain weight loss, with a view to exploit that fact. Is it a particular personality trait that leads to successful weight loss?

Another suggestion was to change the dietetic intervention control group to a wait-list comparison – a control group that serves as an untreated comparison for the behavioural interventions, but still receives access to treatment after the active intervention groups. Gina agreed to incorporate this feedback into her study design.

References

Fletcher, B. C., Hanson, J., Page, N., & Pine, K. (2011). FIT – do something different: A new behavioral programfor sustained weight loss. Swiss Journal of Psychology, 70(1), 25-34. doi: 10.1024/1421-0185/a000035

Lally, P., Chipperfield, A., & Wardle, J. (2008). Healthy habits: efficacy of simple advice on weight control based on a habit-formation model. Int J Obes (Lond), 32(4), 700-707. doi: 10.1038/sj.ijo.0803771

Lally, P., van Jaarsveld, C. H. M., Potts, H. W. W., & Wardle, J. (2010). How are habits formed: Modelling habit formation in the real world. European Journal of Social Psychology, 40(6), 998-1009. doi: 10.1002/ejsp.674

Pine, K. F. B. (2014). Time to shift brain channels to bring about effective changes in health behaviour. Perspectives in Public Health, 134(1). doi: 10.1177/1757913913514705

 (Summary provided by Michele Weber)