Which type of tissue metabolizes food faster and makes it easier to lose weight?

Muscle Tissue.

Fatty Tissue in the body metabolizes (burns) food more slowly then muscle. For this reason, a person with a high fat-to-muscle ratio metabolizes food more slowly than a person of the same weight with more muscle. That is, two people of the same weight may metabolize food at different rates, depending on their distribution of muscle and fat.

In other Words when you start working out and building muscle, your fat turns into muscle making your muscle tissue burn your food faster. Thus the reason for weight loss.