Liquid diet would be the only way to do what you want by Tuesday. I wouldn't recommend it for long term.

What it gets down to for weight loss is take in less than you expand and/or expand more than what you take in. Some things to consider on a longer term:

1. Exercise. Not just cardio type things (running, biking, etc.) but also weight training. You need a good mix of the two to help tone muscles as well as build a strong aerobic system. It will pay off long term as weight training improves your skeletal structure while cardio improves your cardiovascular (heart) system.

2. Less fat. Don't get rid of fat entirely but reduce the amount. Eat less processed foods will help with this as a lot have "hidden fats" in them.

3. Reduce Portion size. The US has become the venue for large portions. We upsize, grandsize, max size everything.. and eat it all because mom always told us to finish our plates. A standard McDonalds combo (reg sandwich, reg fries, coke) is around 1,000 calories. The average person uses about 2,000-2,500 calories. The average diet seems to be close to 3,500 calories (per day) and since 3,500 calories is the amount of a pound, simple math will tell you ... it adds up.

4. Don't rely on the scale. Scales are good at absolute weight but cannot tell the difference between fat and muscle (which tends to be heavier than fat). Use a measuring tape around the waist, hips, thighs, calves, chest areas to see losses there even if weight doesn't decrease.

5. Indulge a little bit. You will have a craving for a sweet or treat. There's nothing wrong with that. Indulge a little once in a while in moderation. Make it a special occassion rather than a daily occurence.

6. Have patience. It took you x number of years to end up here. It should take time to lose it. It ain't going to happen overnight (contrary to some of those pills and such).

7. Don't let set backs become reasons not to continue. It is likely you'll "fall off the wagon". That's ok. Just continue. Try to learn what triggered the "fall" but don't let it become a way to beat yourself up.

Some resources worth checking out:

Body for Life (actually has a decent program and plan. You can use regular foods and avoid the supplements)
Thin for Life (research book on how people maintain their weight loss through the use of a variety of programs such as weigh watchers, Atkins, Jenny Craig, self-made-diets, etc.)

I personally do not advocate the usage of a diet like Atkins as I believe in variety being the spice of life. I've lost 35 pounds since July through bicycling (4-5 days a week) and watching what I eat. I do treat myself to Large Fries and a burger at McDonalds once every two to three weeks but generally stay healthy and make my own. It's paid off in less stress, more confidence, feeling better about myself and better sex drive (*rwaor*).

Hope this helps and good luck.