Switching diets after 6-months does not result in renewed weight loss: a secondary analysis of a 12-month crossover randomized trial.

Catherine P Ward, Priya Fielding-Singh, Anthony Crimarco, Kristen M Cunanan, Matthew J Landry, Christopher D Gardner

Journal: Scientific reports 2024;14(1):9865

PMID: 38684815

Free Full Text on Nature Publishing Group View on PubMed

Plain Language Summary

Weight loss resulting from diet and lifestyle interventions frequently results in a plateau after 6-months, which may be due to individuals losing interest in the diet. Changing weight-loss diets at this point could aid further weight loss, however no study has assessed this. This secondary analysis of a 12-month randomised control trial of 61 individuals aimed to determine whether changing diets after six months could help people continue to lose weight. Adults followed either a low-fat or low-carbohydrate diet for the first six months, then switched to the other diet for the next six months.

The results showed that initially, participants lost weight quickly, but this weight loss slowed down after about three to six months. After switching diets, there was a slight decrease in weight until the nine-month mark, but the rate of weight loss was slower than before.The findings suggest that simply switching diets after six months does not lead to significant renewed weight loss. Participants did not experience a substantial increase in weight loss after changing their eating plan.

It was concluded that the slowing of weight loss is physiological and cannot be changed by switching to a different weight-loss diet. This study could be used by healthcare professionals to understand that changing diets after six months may not effectively promote further weight loss in adults. Individuals need to be prepared psychologically to understand that this is a natural process and not to become demotivated.

Abstract

Weight change trajectory from diet and lifestyle interventions typically involves rapid weight loss followed by a weight plateau after approximately 6 months. Changing from one weight-loss diet to another at the time of the plateau could instigate renewed weight loss. Therefore, our secondary analysis aimed to assess trajectory of weight loss in a 12-month, randomized, cross-over study. Forty-two adults were randomized to eat a healthy low-fat or healthy low-carbohydrate diet for 6 months then switched to the opposite diet for an additional 6 months. Regardless of diet assignment, participants experienced rapid initial weight loss, which slowed between 3 to 6 months. After switching diets at 6 months, weight modestly decreased until 9 months, but at a rate slower than the initial 3 months and slower than the rate from 3 to 6 months. This suggests that the weight loss plateau typically seen at 6 months is physiological and cannot be overcome by simply switching to a different weight-loss diet.

Address: Stanford Prevention Research Center, School of Medicine, Stanford University, Stanford, CA, USA. [email protected].; Department of Population Health and Disease Prevention, Program in Public Health, University of California, Irvine, 856 Health Sciences Rd., Irvine, CA, 92697, USA. [email protected].; Stanford Prevention Research Center, School of Medicine, Stanford University, Stanford, CA, USA.; Quantitative Science Unit, School of Medicine, Stanford University, Stanford, CA, USA.; Sandberg Goldberg Bernthal Family Foundation, San Francisco, CA, USA.; Division of Gastroenterology and Hepatology, Stanford Center for Clinical Research, Stanford University, Redwood City, CA, USA.

DOI: 10.1038/s41598-024-60547-z

Patient Centred Factor

Mediators

Physical Environment

Mind and spirit

Clinical Imbalances

Immune and inflammation Blood Sugar Regulation and Insulin Sensitivity

Modifiable Lifestyle Factors

Diet

Nutrition Evidence Keywords

Weight loss Diet fatigue

Link outs

Free resources

Full Text Sources:

Medical:

https://medlineplus.gov/weightcontrol.html

MeSH Terms: Humans, Weight Loss, Male, Female, Cross-Over Studies, Adult, Middle Aged, Diet, Carbohydrate-Restricted, Diet, Reducing, Obesity, Diet, Fat-Restricted