To tone up, you should be making sure you are burning more calories than you're taking in. Hitting the gym should definitely help with that, but sugars (not just refined) are probably one of the biggest contributers of useless calories to our diets. Red meat isn't what you should worry about - the protein in combination with the gym should help you burn calories faster - it's the cookies, soda, fruit juice (if you drink that) and desserts.
Try replacing the soda and snacks with water, fruits and vegetables. When i'm trying to be healthy, I'll get bags of baby carrots to snack on during the day. Pears and apples are pretty cheap right now. Also, try cutting portion sizes. Eat until you're not hungry, but not until you're full.
Detoxing - which, from what I understand, is basically fasting - is a very unhealthy way to lose weight. You will lose muscle as much as fat, so while you might get smaller, you won't get more toned or healthy that way.