Optimizing Goal Difficulty in a Digital Weight Loss Intervention: The Ignite Pilot Randomized Trial

Area of Science:

• Behavioral Science
• Digital Health
• Obesity Research

Background:

• Goal setting is crucial for behavioral weight loss interventions.
• Harder goals are theoretically more effective than easier goals.
• Limited experimental data exists on goal difficulty in digital weight loss interventions.

Purpose of the Study:

• To experimentally test the impact of easier versus harder goals on weight loss in a digital intervention.
• To assess the feasibility and acceptability of manipulating goal difficulty.
• To compare weight loss outcomes between participants assigned to easier or harder goals.

Main Methods:

• A pilot optimization trial (Ignite) used a 2^4 factorial design.
• 32 adults with overweight/obesity were randomized to easier or harder goals across four domains (calories, steps, eating windows, Red Zone Foods).
• A 10-week digital intervention included daily self-monitoring, weekly lessons, and feedback.

Main Results:

• The study met feasibility and acceptability benchmarks, with 94% retention and high program recommendation.
• Participants achieved a mean weight loss of -4.0% (-3.3 kg) at 10 weeks.
• A harder calorie goal resulted in significantly greater weight loss (-2.3 kg difference) compared to an easier calorie goal.

Conclusions:

• The digital weight loss intervention demonstrated high feasibility, engagement, and acceptability.
• Minor refinements are needed before a larger trial can test goal difficulty efficacy.
• Harder calorie goals show promise for enhancing weight loss in digital interventions.