Background: People who go to gyms tend to adopt obsessive behaviors that can lead them to fear carbohydrates, a condition called carbophobia. The objective of the research was to develop and validate a measurement instrument for carbophobia in a sample of users who go to gyms in a district of Metropolitan Lima - Peru. Methods: The instrument, prepared by the authors, was submitted to content validation through expert judgment with the participation of five nutritionists with a master's degree, reliability analysis after a pilot test that had a sample of 200 gym users, validation of construct by factorial analysis, and obtaining scales by means of the Estaninos test. Results: The instrument presented high reliability for the general score (α = 0.953), and in each of its dimensions: Stagnation in weight loss and training (α = 0.904), Lifestyles (α = 0.953) and Love relationship I hate carbohydrates (α = 0.890), dimensions that were determined by factor analysis. Conclusions: The Carbophobia Measurement Scale is a valid and reliable instrument, and it can be applied in people who go to gyms, being necessary to carry out new studies to determine its usefulness in other population groups.