Most public health organizations make a clear distinction between added sugars (for example, high fructose corn syrup) and naturally occurring food sugars (like the fructose found in fruit). At WHFoods, we rely on the Dietary References Intakes (DRIs) in our analysis of foods and meal plans, and there are actually no DRIs established for naturally occurring sugars in food. Similarly, the MyPlate sugar recommendations from the U.S. Department of Agriculture don't place any limit on naturally occurring sugars.
While we understand the reasoning behind this lack of restriction on naturally occurring sugars, we also believe that paying attention to your intake of natural sugars is worth the effort. Even though your meal plan is more likely to become imbalanced from consumption of added sugars, naturally occurring sugars can still become an excessive part of your diet and throw it out of balance. At WHFoods, we use two basic principles to help us keep naturally occurring sugars in check within our meal plans and our recipes.
First, we like the idea of using glycemic index (GI) to help us determine appropriate amounts of natural sugars. Bananas and watermelon provide a good example of the way we bring GI into our decision-making. The medium banana that we profile on our website contains 14 grams of naturally occurring sugar. But partly because of its good fiber content (3 grams), it qualifies as a low GI fruit. By contrast, the one cup of watermelon on our website contains less naturally occurring sugar (9-10 grams); yet, partly because of its much lower fiber content (about 1/2 gram), it has a medium GI value and for that reason can be challenging to our blood sugar level. Whenever we find the amount of natural sugar beginning to increase in one of our meal plans or recipes, we look more and more exclusively to low GI foods to help offset increasing levels of natural sugar. We encourage you to consider this same approach in your own meal planning. In our article What Is Glycemic Index? you can find a complete list of all WHFoods and their GI value.
Second, we like the idea of keeping the daily amount of natural sugars to about one-third of the total daily carbohydrate level. For example, an 1,800-calorie diet providing 45% percent carbohydrates would contain roughly 200 grams of total carbohydrates, and we would recommend limiting the natural sugars in that diet to about one-third of that amount, or approximately 67 grams. Sometimes we use this one-third carb rule to look at a single recipe, like our 10-Minute Energizing Oatmeal. In this recipe you will find 57 grams of carbs and a total sugar amount of approximately 20 grams. You can see how the natural sugars here represent about one-third of the total carbs. Remember, however, that these guidelines are precisely that—guidelines rather than strict rules. Also remember that whenever the natural sugar amounts begin to cross too far over this 33% percentage level amount, it can be helpful to stick much more closely with low GI foods.
Finally, we want to contrast these natural sugar guidelines with public health guidelines for added sugar intake. For example, the USDA's former Food Guide Pyramid recommended a total of 12 grams added sugar on a 2,200-calorie meal plan. Since one teaspoon of pure granulated sugar contains about 4 grams of this sweetener, 12 grams is the equivalent of 3 teaspoons of added sugar per day. While this amount might seem high, it's important to realize that a single 12-ounce can of cola typically contains 35-40 grams, and the average daily added sugar intake in the U.S. is approximately 80 grams.