Health and behavior change programs play a crucial role in improving health behaviors at individual and family levels. However, these programs face challenges with engagement and retention and typically show modest efficacy. Cognitive load theory is an established and highly used educational theory that proposes individuals have a finite capacity to process new information (“working memory”). Learning, engagement, and performance are negatively impacted when working memory is exceeded. Cognitive load theory is grounded in an understanding of human cognition and conceptualizes different types of cognitive loads imposed on individuals by a learning experience. Cognitive load theory aims to guide the design of learning experiences, considering how the human mind works, leading to more meaningful and effective learning. Cognitive load theory is increasingly applied to domains outside the classroom, such as designing patient and clinical education. Applying cognitive load theory to the design of health programs, their materials, and interfaces can provide insights. By considering the cognitive demands placed on individuals when interacting with health programs, design can be optimized to reduce cognitive load and better facilitate learning and behavior adoption. This may enhance engagement, retention, and effectiveness of programs. Cognitive load theory may be particularly valuable for individuals with diminished working memory due to high levels of mental load and stress. Design principles are presented to consolidate knowledge from cognitive load theory and existing approaches to guide researchers, policymakers, and health programmers. Further research and interdisciplinary collaboration are needed to realize the potential of cognitive load theory in health.

Adolescent obesity is difficult to treat and the optimal dietary pattern, particularly in relation to macronutrient composition, remains controversial. This study tested the effect of two structured diets with differing macronutrient composition versus control, on weight, body composition and metabolic parameters in obese adolescents. A randomized controlled trial conducted in a children’s hospital. Eighty seven obese youth (means: age 13.6 years, BMI z-score 2.2, waist: height ratio 0.65, 69% female) completed a psychological preparedness program and were then randomized to a short term ‘structured modified carbohydrate’ (SMC, 35% carbohydrate; 30% protein; 35% fat, n = 37) or a ‘structured low fat’ (SLF, 55% carbohydrate; 20% protein; 25% fat, n = 36) or a wait listed control group (n = 14). Anthropometric, body composition and biochemical parameters were measured at randomization and after 12 weeks, and analyzed under the intention to treat principle using analysis of variance models. After 12 weeks, data was collected from 79 (91%) participants. BMI z-scores were significantly lower in both intervention groups compared to control after adjusting for baseline values, SLF vs. control, mean difference = -0.13 (95%CI = -0.18, -0.07), P<0.001; SMC vs. control, -0.14 (-0.19, -0.09), P<0.001, but there was no difference between the two intervention diet groups: SLF vs. SMC, 0.00 (-0.05, 0.04), P = 0.83. Both dietary patterns resulted in similar changes in weight, body composition and metabolic improvements compared to control. The use of a structured eating system which allows flexibility but limited choices can assist in weight change and the rigid application of a low fat eating pattern is not exclusive in its efficacy. International Clinical Trials Registry ISRCTN49438757