No way, it doesn't build muscle. However, most bodybuilders eat it in their daily diet.
Here's something i found doing a quick search in google using "oatmeal" "muscle" and "diet."
CARBOHYDRATES
FACT: Carbohydrates are used as energy for your body.
Like protein, ALL CARBS ARE NOT CREATED EQUAL.
Think of carbs as fuel for a fire (wood). Some carbs burn very quickly, like paper. Other carbs burn slowly and for longer duration, like hard wood (oak). Just like any other machine, we need different types of fuel for starting, maintaining, or stoking our fire.
Here’s the technical mumbo-jumbo: The GLYCEMIC INDEX (G/I) is a number scale that ranks foods according to the way they affect your blood sugar levels. High glycemic index foods elevate INSULIN levels quickly and severely. Trust me, BIG DADDY INSULIN is a powerful force.
Insulin controls energy functions in our body. That means fat burning, hunger, fatigue, and solid, steady energy levels are a result of insulin activity.
We can use different types of carbs to our advantage. Let’s go back to our campfire. To start the fire, we need quick burning fuel (paper). On the glycemic index, this equates to high G/I foods. Some of the highest are bagels, carrots, and white rice. These foods tend to give us quick energy but they also make us "crash" early. They create insulin spikes. These spikes are not bad if you know they’re coming and provide an extended energy source also.
Our fire needs hard wood to keep it burning, so we need low G/I carbs to keep us going throughout the day or to help us make it through an intense workout. Some good examples are oatmeal, grapefruit, or yogurt.
There are certain times of the day when your energy stores are low so energy storage is maximized and fat storage is minimized. These times are after waking up (post 8-hour fast) and after working out (aerobics or weight lifting). These are the perfect times to load up 40-50 medium-high carbs. Big Daddy Insulin will use carbs very efficiently at these times, restoring energy reserves and preparing for our next stressful event (work-out or another 8-10 hour fast).
