There are individuals who claim to have lost considerable amounts of weight by using an electric bike. A recent prospective cohort study however found that people using e-bikes have a higher BMI. By making the biking terrain less of an issue, people who wouldn't otherwise consider biking can use the electric assistance when needed and otherwise pedal as they are able. This means people of lower fitness levels or who haven't cycled in many years can start enjoying the many health benefits E-bikes have to offer. 
Electric Bike Technologies has been delivering the best experience in electric bike kit conversion since the company was founded in 2008. Driven by a respected founder and a team of dedicated electric bike enthusiasts, the E-BikeKit™ electric bike conversion systems have been sold worldwide to thousands of electric bike riders and fostered partnerships with some of the best brands in the bicycle industry. The company has been featured on NBC’s Good Morning America and the E-BikeKit system is the only electric bike kit system distributed by J&B Importers, the largest bicycle distributor in the United States.
Gearing: none (many hub motors, one motor revolution = one wheel revolution), fixed gear reduction for more torque, varies when geared motor drives the chain through the bicycle gears which increases torque about 50% (in low gear) for better hill-climbing and offers better top-end speed (in high gear) than direct drive systems using motors of similar wattage.
In a single screen, with simple controls, the BionX command console displays important travel information and allows the rider to easily switch between different power modes. In assistance mode, the display indicates the power supplied by the battery. In generative mode, the display indicates the energy transmitted to the battery. The console is a multifunctional odometer and displays:
E-bikes mostly use motors and battery options from a few major suppliers: Bosch, Yamaha, Shimano, and Brose. A few other brands exist, but are less reliable or powerful. Some, like the Yamaha system, have more torque and others are quieter. But generally all four make good options. Look for motor output (in watts) which will give you an idea of total power. But watt hours (Wh) is perhaps a better figure to use—it takes into account battery output and life to give a truer reflection of power.