Alli is the over-the-counter version of the drug orlistat, a weight-loss aid that blocks the absorption of fat in your intestines and reduces the number of calories your body can use from the food you eat. Alli works by blocking the enzyme lipase so your body cannot break down dietary fat and it's passed through your digestive system. Alli has very little immediate effect on blood sugar, as it interferes with dietary fats and not carbohydrates, but losing weight will improve insulin sensitivity and help stabilize blood sugar long-term.
Alli and Diet
Although Alli is a weight-loss pill, the Alli program includes a very specific diet; consuming too much fat -- more than 15 g of fat per meal -- can have negative consequences. Because Alli allows fat to pass through your body undigested, side effects can include diarrhea, oily flatulence that can stain your clothing and frequent or uncontrollable bowel movements. Limiting fat intake is critical to minimize these side-effects. Often when one macronutrient is limited, consumption of the other two increases. Protein and carbohydrates are not restricted, although portion control and calorie consumption is monitored.
Blood Sugar
Carbohydrates have the biggest impact on your blood sugar levels. Although the drug orlistat has no affect on blood sugar, changing your diet to include less fat and more carbohydrates could potentially increase blood sugar. You can minimize the impact on glucose levels by choosing high-fiber complex carbs instead of sugar and starchy carbs. Following a low-calorie eating plan should help eliminate excess simple carbs from processed snacks and junk foods.
Weight Loss
In the long-run Alli may help to stabilize blood sugar by promoting weight loss, healthy eating habits and physical activity -- all of which will reduce insulin resistance. Excess body fat interferes with how efficiently your body can use insulin, making it less effective. By building lean muscle and losing fat your cells can become more sensitive to insulin -- which will help reduce high blood sugar.
Safety Concerns
The Mayo Clinic notes that blocking the absorption of fat also hinders your body's ability to absorb fat-soluble vitamins and recommends that you take supplemental vitamins A, D and E. Alli is only designed for people who are overweight and shouldn't be used for people within a healthy weight range. If you have thyroid problems, diabetes, liver disease or difficulty absorbing food -- such as Crohn's disease or a previous gastric bypass -- speak to your doctor before using Alli. Alli is only meant to supplement weight loss, not to be used as a replacement for diet and exercise.
