Can I Modify the South Beach Diet?

Regarding the South Beach diet, I did Barry's Boot Camp around the same time I started South Beach and cutting out carbs while doing cardio really wore me out - I had no energy! Any modification suggestions? —Natalie, Los Angeles

Great question, Natalie! Bear with me for a second while I help explain the science behind why you felt tired.

The reason you feel tired in the beginning on the South Beach (or Atkin's diet) is because your body is adjusting from using sugar TO stored fat for its energy. In order for your body to use its fat stores, it first has to convert the fat to something called "ketones." This process of conversion is also known by doctors and South Beachers as being in "ketosis." Basically, ketosis means that your body is now using fat as energy because there's no free sugar available.

The first few days in ketosis can make you feel grouchy, crabby, sluggish, low energy, and you might have bad breath. Generally this subsides after the first few days and your body adjusts to its new energy source. Some studies suggest that the brain actually prefers ketones to sugar for energy. Many people in ketosis report feeling more balanced, calm, and alert. Perhaps this is due to the stable blood sugar levels, but we really do not know.

I wouldn't modify the diet initially. In fact, I recommend following the diet to the letter for the first two weeks. There are enough "good carbs" included in the South Beach "induction" phase to keep some glucose in your system. Remember, making changes to your metabolism takes time and so you may not feel an overnight improvement, but over the course of several days and weeks you should adjust.

I'd also strongly recommend that you work with a nutritionist familiar with low glycemic diets, which is what the SB diet is, or a doctor who can customize the diet along with making any supplementation recommendations. You should also make sure you clear all of this with your doctor. It's important to monitor your blood work regularly to check your blood glucose levels, triglycerides, thyroid function, and other indicators when you begin a diet or fitness program. A doctor can be a real ally in your weight loss adventure!