Low-energy diets are often used for weight loss interventions, but the success rate can vary…
It’s an age-long debate: what’s better for sustained long term weight loss: a rapid approach, since such changes might lead to larger losses in the long-term, or a slower, steadier approach, because that’s the best way to keep it off?
Advocates for the fast approach say that it’s the best way to achieve greater long-term weight loss, but research has also shown that people who lose a lot of weight very quickly often experience more rapid weight regain down the track.
Working out the optimal rate of weight loss is the subject of a recent study conducted by the University of Florida. Their investigation, conducted over 18 months, was designed to determine whether slow or fast initial rates of weight loss are better for achieving long-term weight reduction, and less weight regain.
This study monitored 298 healthy women, aged 50 to 75, with a mean baseline weight of 96.5kg and mean BMI of 36.8. The initial phase of the study was a 6-month lifestyle intervention, including 24 group behavioural sessions with a focus on reduced caloric intake and increased exercise to achieve approximately 0.45 kg of weight loss per week. In this stage, participants were encouraged to consume 1,200 kcal/day and reach either 10,000 steps per day, or 3,000 steps above their baseline level.
Following this initial stage, a 1 year extended care program commenced, where each participant was contacted twice per month though either group sessions, telephone or newsletter.
During the first month of the intervention, participants were divided into three groups:
- The fast group lost weight at a rate of 680g or more a week
- The moderate group lost between 230g and 679g a week, and
- The slow group lost up to 229g a week.
Data for 262 participants was validated for the final results analysis.
Between baseline and 6 months, the mean weight loss for each group was as follows:
- Fast group (69 women) – 13.5kg
- Moderate group (104 women) – 8.9kg
- Slow group (89 women) – 5.1kg.
Following the 12-month maintenance period, the mean weight loss increased slightly; all groups regained some of the weight they had previously lost:
- Fast group – 10.9kg
- Moderate group – 7.1kg
- Slow group – 3.7kg
Overall, there was no significant difference in weight regain between 6 and 18 months for any of the groups, however the fast group was 5 times more likely to achieve 10% weight loss at 18 months than the slow weight loss group.
So what was it that set the fast group apart from the others? In analysing the results, a few factors emerged. Participants in the fast group:
- Attended significantly more sessions than those in the slow group
- Completed significantly more food records
- And consumed significantly fewer calories
Participants in the moderate group also completed more food records and walked more steps per day than the slow group.
What this means for your weight loss clients
Previous studies have found a connection between larger initial weight loss and rapid weight regain, but did not include ongoing support or contact with participants after the initial intervention period. It is possible that the support period included in this trial was a factor in helping participants maintain their weight loss for an extended period of time.
This study shows that participants who lose weight at a greater initial rate experience weight losses in the short-term, are not more susceptible to weight regain than participants who lose weight at a slower rate, and after 12 months of maintenance, achieved larger overall losses from their initial starting weight.
Reference: Nackers, L. M., Ross, K. M., & Perri, M. G. (2010). The association between rate of initial weight loss and long-term success in obesity treatment: does slow and steady win the race? International Journal of Behavioral Medicine, 17(3), 161–7. doi:10.1007/s12529-010-9092-y
How do you balance your clients’ desire for rapid weight loss with realistic and long-term lifestyle change? Share your insights in the comments below.