According to the US Centers for Disease Control, more than 42% of adults are classified as obese, and approximately 74% of US adults are classified as overweight (body mass index of 25.0 to < 30 kg/m2) or obese (>30 kg/m2) (Ow/Ob). The costs on human health are profound, increasing the risk of heart disease, stroke, type 2 diabetes, and certain cancers, and ultimately increasing morbidity associated with these chronic diseases. Obesity and the negative sequelae inflict staggering economic costs, estimated at $147 billion, and that was in 2008. Therefore, understanding and developing interventions that can help address Ow/Ob can reduce the risk of chronic disease, reduce healthcare costs, and likely improve quality of life.~One such intervention has been through altering diet and/or physical activity. However, prior systematic review and meta-analysis suggests that when comparing diet alone vs. exercise alone, dietary interventions result in ~3-fold greater weight loss (11 vs 3 Δkg). While the additional benefits of exercise are not be discounted, engaging dietary approaches can be a highly effective way to promote weight loss. Caloric restriction (CR) has long been touted as an effective method of inducing weight loss, although there are also issues with adherence and maintenance with such an approach. This study is seeking to understand the acute metabolic changes with engaging in a 3-day caloric restriction, which would typically be part of an intermittent fasting dietary regimen.~Specific Aim 1. Document the efficacy of the 3 day IF/CR on inducing short term weight loss, the nature of the weight loss changes (body composition), changes in anthropometrics (waist and hip circumference), changes in resting metabolic rate and changes in metabolic flexibility (relative utilization of fats versus carbohydrates).~Specific Aim 2. Explore the physiological responses to the 3 day IF/CR with the Plexus 3 day reset program through analysis of blood plasma for levels of insulin, glucose, lipid profile (total cholesterol, high- and low-density cholesterol (HDL/LDL)), pro- and anti-inflammatory mediators (Tumor Necrosis Factor-alpha, TNFa and Cortisol, respectively), ketones, thyroid stimulating hormone (TSH), and hormones related to hunger and satiety and thus energy intake (protein YY (PYY), neuropeptide Y (NPY), Ghrelin, and Leptin).~Specific Aim 3. Ascertain any possible changes in clinically relevant parameters such as heart rate, heart rate variability (HRV), blood pressure (central and peripheral), and vascular stiffness (augmentation index, AIx).~Hypothesis: The investigators hypothesize that the nutritional intervention will induce weight loss, changes in anthropometrics/body composition (i.e. decreased body water), resting metabolic rate, and alterations in metabolic flexibility. These measures will be explained, at least, in part, by alterations in specific blood biomarkers. The investigators also hypothesize that the 3 day IF/CR will result in improved indicators of cardiovascular health.
The purpose of this study is to document the efficacy of a 3 day intermittent fasting/caloric restriction (IF/CR) using the Plexus® 3 day reset program on body weight as well as regulatory parameters of metabolism and metabolic flexibility. This study will provide data on the acute efficacy regarding the program but also identify the potential underlying physiological mechanisms through which the dietary intervention may elicit improvements, and the participant experience of the program. Collectively, this will provide a window into the possible adaptations with a longer-term dietary intervention.