You’re an HR manager, a volunteer looking to raise money for your church, or just a law-abiding citizen and wondering if it’s legal to engage in a DietBet.
It is. Let’s start with the legal definition of gambling (in the US):
A person engages in gambling if he stakes or risks something of value upon the outcome of a contest of chance or a future contingent event not under his control or influence...
Gambling entails betting on something beyond your control or influence, like a roulette wheel or the Packers covering the spread this Sunday. When you put money on the line in a dietbet, you are betting on something that’s within your control: your weight. (Believe it or not, your weight is technically under your control.) Thus it’s skill-based, and is, in the eyes of the law, not gambling.