MIAMI (CBSMiami) – Being overweight is tough enough as an adult, but for children it can lead to bullying, low self-esteem and other problems. One 12-year-old decided he was tired of being picked on, upset about his weight and appearance; so he decided to change his life.

“I started this about two years ago because I was tired of getting bullied,” said Marshall Reid.

READ MORE: Miami ex-Proud Boys leader Henry 'Enrique' Tarrio to stay jailed until Capitol riot trial

The North Carolina native told CBS4’s Marybel Rodriguez it all had to do with his weight.

“They (kids) said you are fat because of your mom or your mom is stupid and fat stuff like that every single sentence had to do with fat,” Reid said.

Marshall said he finally snapped and was determined to lose some weight and he did so by portion control. He was on a mission. At first he was on it alone then his family joined him.

READ MORE: Judge gives initial OK to $1B deal in Surfside condo collapse

Marshall said he turned all the negative energy and thoughts into something positive. With that in mind, he began to lose weight and exercise. He said he felt so great that with the help of his mother wrote a book about it call “Portion Size Me”.

Portion Size Me is a kid-friendly plan to a healthier family with dozens of kid-friendly recipes and his personal journey along the way. Marshall even kept a video diary where for 30 days he posted the videos on YouTube.

Several months ago the Marshall’s purchased a 1974 Airstream and this summer, the family will be traveling across the country to help other families along the way.

One of Marshall’s first stops was at Camp Unbeatables in Doral where he spoke to a group of campers about his journey and gave them tips on how to stay and live a healthy life.

Marshall set six goals for himself and his family from eating healthy to exercising. So far, he said they are on track. As for a personal goal, he hopes his story and book will help other kids facing similar issues.

MORE NEWS: Fort Lauderdale Police: 2 Stabbed, 1 In Custody

For more on Marshall Reid and “Portion Size Me,” you can visit his website

Marybel Rodriguez