Randomized Controlled Trial Examining the Ripple Effect of a Nationally Available Weight Management Program on Untreated Spouses

Obesity (Silver Spring). 2018 Mar;26(3):499-504. doi: 10.1002/oby.22098. Epub 2018 Feb 1.


Objective: For married couples, when one spouse participates in weight loss treatment, the untreated spouse can also experience weight loss. This study examined this ripple effect in a nationally available weight management program.

Methods: One hundred thirty dyads were randomized to Weight Watchers (WW; n = 65) or to a self-guided control group (SG; n = 65) and assessed at 0, 3, and 6 months. Inclusion criteria were age ≥ 25 years, BMI 27 to 40 kg/m2 (≥ 25 kg/m2 for untreated spouses), and no weight loss contraindications. WW participants received 6 months of free access to in-person meetings and online tools. SG participants received a weight loss handout. Spouses did not receive treatment.

Results: Untreated spouses lost weight at 3 months (WW = -1.5 ± 2.9 kg; SG = -1.1 ± 3.3 kg) and 6 months (WW = -2.2 ± 4.2 kg; SG = -1.9 ± 3.6 kg), but weight losses did not differ by condition. Overall, 32.0% of untreated spouses lost ≥ 3% of initial body weight by 6 months. Baseline weight was significantly correlated within couples (r = 0.26; P < 0.01) as were weight loss trajectories (r = 0.52; P < 0.001).

Conclusions: Evidence of a ripple effect was found in untreated spouses in both formal and self-guided weight management approaches. These data suggest that weight loss can spread within couples, and that widely available lifestyle programs have weight loss effects beyond the treated individual.

Trial registration: ClinicalTrials.gov NCT03042208.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Female
  • Humans
  • Male
  • Middle Aged
  • Obesity / therapy*
  • Spouses / education*
  • Weight Loss / physiology*
  • Weight Reduction Programs / methods*

Associated data

  • ClinicalTrials.gov/NCT03042208