Weilos, which debuted at Y Combinator's Summer 2013 Demo Day last month, is a weight loss coaching service that utilizes people's past experiences to help others lose weight.

The peer-to-peer network connects people with weight loss success stories to those who are just beginning their journey, or have tried to lose weight before without reaching their goals. Those looking to use the program must provide Weilos with a brief summary of why he or she wants to use the product before beginning the 14-day free trial in order to ensure all users will be serious about the program.

"[The user must] submit the reason why they want to lose weight," co-founder Ray Wu told MobiHealthNews. "If it seems like they're motivated we accept them. We just want to make sure everyone that signs up is committed to losing weight. Our coaches have a lot of members, what we don't want is for people who aren't serious to take up coach's time and effort, and then leave the program."

After the trial period, users can choose a coach, some of whom offer the program for free while others charge $19, $39 or $59 per month. Because the point of Weilos is for the user to find a coach that suits his or her specific needs -- moving away from the one-size-fits-all approach -- the company looks for key differentiators in all program participants such as age, how much weight loss the user is looking for and what life constraints the user has.

Weilos also goes through a screening process to approve each coach, which involves a phone conversation and background questions about the potential coach's weight loss story. Weilos also tells coaches to avoid sensitive topics and just stick to the basics of weight loss.

"We tell the coaches, only give nutrition and exercise advice, and not to talk about medical conditions or anything with certain conditions that people have," Wu said.

If anything does come up that the coach doesn't feel comfortable talking to members about, the coach can talk to a Weilos team member about it, but Wu said none of those issues have come up yet.

So far the program consists of 12 active coaches that have three or more members and 15 that have been approved. Over 200 have applied for coaching positions. Currently 75 people are subscribed as active members and around 1000 are on the waiting list. While the current goal is for each coach to have at most 10 members subscribed to his or her program, Wu believes that after developing a more streamlined system, coaches will be able to handle many more.

Moving forward, Wu plans to make the program almost completely mobile.

"Right now we have a website," Wu said. "We're developing an app for iOS and Android. This will be close to 100 percent mobile. For people to engage with the app every single day multiple times a day it just has to be on mobile. Our goal is to reach millions of people."

The company is also looking into have a completely free version of the app in order to reach such large audiences.

Wu is "not focused on the business model at all," he says, because he believes once the company can "figure out the right dynamics," to get people to "pay more attention and be more accountable to make the right choices," the whole business model and monetization will take care of itself.

While other weight loss coaching programs exist, like San Francisco-based Sessions, which developed a program that links people to coaches that offer encouragement and Chicago-based Retrofit, which uses healthcare professionals as coaches, Wu believes using people who have lost weight themselves as coaches sets Weilos apart.

"It turns out that people who have lost weight have extremely high intrinsic motivation for helping others achieve the same success," Wu said. "They are very effective because of practical knowledge but also because they inspire others."