Overview
The primary aim of this randomized controlled trial is to examine the effects of a 4-week high-intensity interval training (HIIT) and time-restricted eating (TRE) intervention on cardiometabolic biomarkers in adolescents and young adults.
Description
As of 2015, an estimated 2 billion individuals were overweight (body mass index [BMI] ≥ 25 kg/m2), and one-third of them were obese (BMI ≥ 30 kg/m2). Obesity has become a serious health concern due to its related comorbidities, including cardiovascular disease (CVD) and type 2 diabetes (T2D). While adolescents and young adults are considered low risk for the development of CVD, individuals with obesity are still at a greater risk of CVD development than individuals without obesity. Changes to dietary and fitness habits are currently the first-line recommendations for preventing weight gain and improving cardiometabolic health in adolescents and young adults.
Caloric restriction (CR), which involves reducing caloric intake by up to 50% of normal daily calorie intake, is a common dietary intervention approach for weight management and improving cardiometabolic health in adolescents and adults with obesity.9 However, studies have shown that CR is hard to maintain, and individuals tend to regain the weight after the intervention is completed. Time-restricted eating (TRE) has been proposed as an alternative to calorie restriction (CR). TRE, a type of short-term fasting, is defined as periods of no caloric intake followed by periods of ad libitum (as much as desired) caloric intake. The fact that TRE does not intentionally limit energy intake, whereas CR does, could make it more appealing to individuals in terms of adherence, acceptability, and efficacy. TRE is an effective strategy in reducing body fat percentage and waist circumference in adolescents and adults with obesity.
Moreover, high-intensity interval training (HIIT), which involves repeating short periods of intense activity followed by low-intensity breaks, has been shown to be effective in improving cardiometabolic health (including lipids, blood pressure, and insulin sensitivity) in adults with obesity compared to other traditional exercises. In addition to its benefits on cardiometabolic health, previous studies have suggested that HIIT can be a time-efficient strategy to enhance body composition and cardiopulmonary fitness in adults with obesity.1
However, it is unknown if TRE or HIIT will produce a greater improvement in cardiometabolic health. Therefore, the goal of this study is to examine the independent effect of a 4-week TRE and HIIT intervention on cardiometabolic biomarkers in youth and young adults.
Eligibility
Inclusion Criteria:
- Adolescents (age 14-17 years old with sex- and race-specific BMI percentile ≥85th) and young adults with overweight and obesity (age 18 to 30 years old with BMI ≥25 kg/m2)
Exclusion Criteria:
- Chronic medical conditions: heart disease, arrhythmias, diabetes, thyroid disease, bleeding disorder, history of pulmonary disease, hypertension, hepatorenal disease, musculoskeletal disorder, neuromuscular/neurological disease, autoimmune disease, cancer, peptic ulcers, anemia, or chronic infection (HIV).
- Have taken any heart, pulmonary, thyroid, anti-hyperlipidemic, hypoglycemic, antihypertensive, endocrinologic (e.g., thyroid, insulin, etc.), emotional/psychotropic (e.g., Prednisone, Ritalin, Adderall), neuromuscular/neurological, or androgenic medications (anabolic steroids).
- Have a pacemaker.