Butter is rich in saturated fats, making it a bad choice for a heart healthy diet. Butter is also rich in calories, making it a poor choice for a calorie-conscious dieter as well.
Fit Day reports that a stick of butter contains more than 820 calories. Just a pat of butter, which equals teaspoon, contains about 36 calories by itself.
Butter is also rich in cholesterol, boasting 11 g per pat. Butter also contains little to no carbohydrates and no dietary fiber.
While margarine is often considered to be a suitable substitute for butter, it also contains about 102 calories per tablespoon. While butter contains very little sodium, margarine contains about 44 mg of sodium, but no dietary fiber.
Even Smart Balance's buttery spread contains 90 calories per tablespoon and 90 g of sodium, as well. It contains no cholesterol, though, and has other nutritional points worth considering, including no trans fat.