Adherence and Dietary Composition during Intermittent vs. Continuous Calorie Restriction: Follow-Up Data from a Randomized Controlled Trial in Adults with Overweight or Obesity.

Sarah T Pannen,Sandra González Maldonado,Tilman Kühn,Cornelia M Ulrich,Mirja Grafetstätter,Laura F Gruner,Cora Watzinger,Rudolf Kaaks,Ruth Schübel,Karin Nischwitz,Tobias Nonnenmacher,Solomon A Sowah

doi:10.3390/nu13041195

Abstract

Although intermittent calorie restriction (ICR) has become popular as an alternative weight loss strategy to continuous calorie restriction (CCR), there is insufficient evidence on diet quality during ICR and on its feasibility over longer time periods. Thus, we compared dietary composition and adherence between ICR and CCR in a follow-up analysis of a randomized trial. A total of 98 participants with overweight or obesity [BMI (kg/m2) 25–39.9, 35–65 years, 49% females] were randomly assigned to ICR, operationalized as a “5:2 diet” (energy intake: ~100% on five non-restricted (NR) days, ~25% on two restricted (R) days), or CCR (daily energy intake: ~80%). The trial included a 12-week (wk) intervention phase, and follow-up assessments at wk24, wk50 and wk102. Apart from a higher proportion of energy intake from protein with ICR vs. CCR during the intervention (wk2: p < 0.001; wk12: p = 0.002), there were no significant differences with respect to changes in dietary composition over time between the groups, while overall adherence to the interventions appeared to be good. No significant difference between ICR and CCR regarding weight change at wk102 was observed (p = 0.63). However, self-reported adherence was worse for ICR than CCR, with 71.1% vs. 32.5% of the participants reporting not to or only rarely have followed the regimen to which they were assigned between wk50 and wk102. These results indicate that within a weight management setting, ICR and CCR were equivalent in achieving modest weight loss over two years while affecting dietary composition in a comparable manner.

Highlights

The increasing prevalence of overweight and obesity worldwide indicates the need for feasible weight reduction strategies [1]
Data from the HELENA Trial (Healthy nutrition and energy restriction as cancer prevention strategies: a randomized controlled intervention trial), a three-armed, randomized controlled open-label trial carried out to evaluate the metabolic effects of intermittent calorie restriction (ICR), operationalized as the “5:2 diet”, compared to continuous calorie restriction (CCR) over one year, were used for exploratory post hoc analyses
Weight loss from baseline to a follow-up assessment after two years was similar with ICR (−4.3% ± 1.0%) and CCR (−5.0% ± 1.1%)

Summary

Introduction

The increasing prevalence of overweight and obesity worldwide indicates the need for feasible weight reduction strategies [1]. Several clinical trials have reported equivalent weight reduction with ICR as with CCR in the short term [9,10,11,12] and over the course of one year [13,14,15,16]. Little is known about the nutrient and food composition of ICR diets [10,19,20]. A previous study that analyzed nutritional composition during ICR and CCR showed that ICR was related to unfavorable food choices with regard to the intake of fruits and berries, vegetables, fiber, vitamin C and sugar compared to CCR, indicating the need for further research on this topic [20]

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Methods

Conclusion