Conventionally sweetened foods are verboten during all four phases of the Atkins diet plan, but it's especially important not to consume them during phase one, a two-week period known as "induction." Not only are sweets forbidden in induction, so are all carbohydrate-rich foods, including bread, pasta, rice, beans and fruit. Later phases allow limited amounts of complex carbs, but sugar is always a no-no.
Making the Switch
The goal of induction is to quickly transition the body from glucosis -- its usual process of burning glucose or its stored form, glycogen, for energy -- to lipolysis, or burning fat. To do that, dieters must forgo all simple sugars and eat only proteins, pure fats and 20 grams of net carbohydrate per day obtained from a limited selection of low-carb vegetables such as leafy greens and cauliflower. You need not limit your calories, however. Lobster with drawn butter? Go for it.
It takes about 48 hours for you to burn through your glycogen reserves in the induction phase and switch to using fat stores for energy. During the transition phase, some Atkins dieters experience uncomfortable symptoms such as headache, malaise, weakness and irritability, known colloquially as "Atkins flu" in the low-carb community. Cravings for carbs, and for sweets in particular, can be intense the first few days; it's a sign your body and brain are withdrawing from their preferred energy source.
If you experience cravings for sweets, keep in mind that ingesting any sugar will send you back to square one: Your body will immediately stop burning fat and revert to glucosis. A 1.55-ounce milk chocolate bar, for example, contains 26 grams carbohydrate -- already 6 grams over the daily limit for induction. Depending on the number of carb grams you consume, it may take from a few hours to two days for your body to exhaust its new load of glycogen and get back to burning fat.
If you must cheat with something sweet, choose from among the low-carb fruits that are allowed in the later phases of Atkins, particularly berries. One cup of fresh raspberries, for example, contains fewer than 15 grams of carbohydrate; because 8 grams of those are from indigestible fiber, the "net" or "usable" carbs amount to just 7 grams. Sprinkle them with a sugar substitute -- the Atkins program recommends sucralose -- and you may be able to satisfy your craving without interrupting fat breakdown.