The Nazir (Numbers 6:1-21) is a man or a woman who voluntarily accepts additional restrictions upon him or herself, thereby achieving a level of sanctity above the usual. The Nazir state has a time limit, set by declaration when it begins. When it ends, the person brings an offering to the Temple, and returns to normal life.
Despite the Torah’s endorsement of being a Nazir, the offering for returning to regular status is described as a sin offering. The sages noted this and concluded that in fact assuming unnecessary restrictions is not a Torah ideal. Sometimes it may be necessary, if it’s being done to curb an excessive life habit, but intrinsically, both extremes – gluttony and asceticism – contradict our purpose on earth.
God didn’t merely put us in a beautiful world in order to tempt us. We are here to enjoy it and to appreciate it. Says the Jerusalem Talmud (end of Kiddushin): “[When a person passes to the Next World] they will have to answer for every fine fruit that they beheld but did not taste.”
Enjoy life, enjoy the world, but be respectful and reasonable.