You're not digesting food efficiently.
The reason you aren't bloated in bthe morning is because you went probably 10 hours without a meal. Maybe you would benefit from probiotics, or magnesium (which helps your intestines move food along). You could also have a certain type of food that bloats you, like dairy products or wheat products.
Hello~I agree with the other poster, you are not digesting your food properly, adding a good, high potency probiotic would benefit you greatly, also a good multi mineral and vitamin supplement.
Have you been tested for food allergies, if not, it might be a good idea to suggest to your PCP, many times food allergies and sensitivities can cause bloating.