I have asthma, but don't like to take inhalers because people say it makes you chubby?

No... Systemic steroids can cause weight gain but inhaled steroids are used because very little of it goes systemically, thus avoiding this side-effect.
Listen to your docot. I assume you are concerned about steroid inhalers. But these are the foundation of therapy for recurrent, persistent asthma (occurring more than 2 days per week or 2 nights per month). It targets the inflammation in the airways which can actually eventually damage the tissue. Treatment with inhaled steroids helps patients maintain their lung function.