It's how landlords (in Canada anyways) get around not renting to people they don't have a "good feeling" about, but pass all the paper requirements. Simply deny, and don't give a reason, you're not required to, you just can't deny based on protected class. In some cases, you can deny based on safety; such as if your business is not equipped to handle obese people, and they could pose a threat to their own, other customers, or employees' safety, for example a barbershop or a horseback riding outfit (like was featured here a while back). Of course, some fatties ARE actually disabled too, due to weight complications. Even if fat is not legally protected, remember there are Human Rights Tribunals, which basically operate outside the law, and can really ruin your day. So don't say "get out of here fatty!', just say "get out of here!".