Even more important than shopping for healthy foods: actually eating them. When you get home from the store or farmer's market, bounty of fruits and veggies in tow, wash and chop them right away and store in a pretty glass container in your fridge. "Studies show that spending more time on food prep is linked to better eating habits," says Dr. Lipman. It's all about convenience—if they're ready for you, you'll grab them in a pinch. If not? It's chips and dip time. You can also do this with other foods, like making a batch of quinoa for the week or roasting a bunch of veggies to throw together for quick lunches.
But the psychological or spiritual effect can't be discounted, says Dillard. "People love the idea of cleansing, of purification rituals, going to the Ganges, to the spa. It has powerful psychological, religious, spiritual meaning. That has its own positive effect on health. But we need to separate that from saying this is science or good medicine."
In general, healthy eating ingredients are found around the outer edges of most grocery stores, while the center aisles are filled with processed and packaged foods that aren’t good for you. Shop the perimeter of the store for most of your groceries (fresh fruits and vegetables, fish and poultry, whole grain breads and dairy products), add a few things from the freezer section (frozen fruits and vegetables), and visit the aisles for spices, oils, and whole grains (like rolled oats, brown rice, whole wheat pasta).
Avoid alcoholic drinks (such as wine, beer, and spirits) during the cleanse. Alcohol is metabolized in the body mainly by the liver. It is broken down briefly to acetaldehyde, a chemical that has the potential to damage liver cells and body tissues, before it is further broken down and eliminated from the body. Besides lightening the load on your liver, avoiding alcohol (and caffeine) for the week can help to shift habits you've cultivated.
Some still consider fasting -- in any form -- to be "out there." "When I review diets that are not based on science, the question I ask myself is: Would I feed them to my family? In this case, the answer is a clear no," says Susan Roberts, PhD, chief of the Energy Metabolism Laboratory at the Jean Mayer USDA Human Nutrition Research Center on Aging and a professor of nutrition at Tufts University in Boston.