Fast or slow weight loss: which is better?

(11-15-2014) According to current guidelines for dietitians it Lose weight and fat effectivelyis better to lose weight in a slow gradual manner than losing it quickly to maintain weight loss. Because there is hardly any scientific basis for this recommendation Australian scientists started a large scaled study to the effects of the rate of weight loss on weight maintenance. This article describes their research, results and their conclusions on which is better: fast or slow weight loss.

What did the researchers do?

For this large scale study 200 test subjects with a BMI of 30-45 (obesity) were recruited. The subjects were randomly divided over two groups: One group that aimed to lose weight slowly and gradually during 36 weeks and a group that lost the same amount of weight in only 12 weeks. Both groups were put on an energy restricted diet, but the rapid weight loss group’s diet had a larger calorie deficit. The aim of both weight loss periods was to lose 15% of the subjects’ starting weight and the diet of both groups was adjusted accordingly. Subjects were included into the maintenance program when they had lost at least 12,5% by the end of the 12 or 36 week period. In total 189 subjects were eligible to continue in the maintenance phase in which all subjects followed the same maintenance diet during 144 weeks. During the whole research period, the researchers regularly measured the body weight of all the subjects. At the end of the maintenance period they investigated if there was a difference between the rapid weight loss group and the slow weight loss group.

What were the results?

The results are depicted in the figures below.

Weight loss phase

Figure 1: Body Weight during the Weight Loss Phase.











Weight regain phase

Figure 2: Body Weight during the Weight Maintenance Phase











Succesful participants

Figure 3: Percentage of participants that reached weight loss goal.











The participants in the rapid weight loss group, obviously lost weight more quickly and seemed to gain weight more slowly during the weight maintenance phase, but no significant differences were found between both groups concerning weight regain. However there was a significant difference in the amount of subjects that succeeded in reaching the weight loss goal of 15% of initial body weight.

What did the researchers conclude?

The researchers concluded that there is no difference in weight regain after rapid or slow weight loss. They did discover a difference in the number of people who were successfully able to reach the target amount of weight loss at the end of the weight loss phase. They therefore recommend to adjust dietitian guidelines accordingly.

What does this mean for me?

-The rate at which weight is lost does not influence the rate at which weight is regained or the risk of regaining it.

-Body weight and body composition both are a result of your lifestyle. When you have lost weight using a diet and start to take up your old dietary habits again, you will regain weight no matter what diet you followed beforehand.

-Permanently following a healthy diet and lifestyle will be much more effective in helping you  lose unwanted weight and body fat and keep it off.

See also:

-How to lose weight and fat effectively

-Strength training for weight loss

Cardio training for weight loss


-Purcell, K., Sumithran, P., Prendergast, L.A., Bouniu, C.J., Delbridge, E., Proietto, J. The effect of rate of weight loss on long term weight management: a randomised controlled trial. The Lancet Diabetes & Endocrinology 2014, in press.