Assessing “Low-Carb” Products

1. Sugar-Free Does Not Necessarily Mean “Safe” for Diabetics 

This is a good opportunity to emphasize the sources of carbohydrates and how they are metabolized in the body. Explaining to patients that the carbohydrate in foods is the only nutrient affecting postprandial glucose levels, and encouraging the intake of planned amounts of carbohydrate, can improve metabolic control.

2. Sources of Carbohydrates in a Product 

It is very easy to disregard “raw” ingredients, such as flour, in a product. It is common to hear about clients making cakes and other pastries with “artificial sugars” and not counting flour as a carbohydrate serving (Fig. 1).

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Figure 1 A sugar-free product.

3. Sugar Alcohols Count 

Sugar alcohols are sugar replacers, and are neither sugars nor alcohol. Sugar alcohols generally pass through the small intestine and into the large intestine, where they are digested by fermentation. Consequently, severe diarrhea is a common symptom when sugar alcohols are included in the diet. They are partly absorbed and metabolized by the body and, as a result, contribute fewer calories than most sugars, and they do not elevate blood glucose as much, giving them a low glycemic index. The commonly used sugar alcohols include sorbitol, mannitol, xylitol, maltitol, maltitol syrup, lactitol, erythritol, isomalt, and hydrogenated starch hydrolysates. Their calorie content ranges from 1.5 to 3 calories per gram, compared to 4 calories per gram for sucrose or other sugars. The American Dietetic Association recommends that persons with diabetes who are managing their blood sugars with the carbohydrate-counting method “count half of the grams of sugar alcohol as carbohydrates since half of the sugar alcohol on average is digested.”4

4. Net Carbs Is Not the Total Carbohydrate Count 

“Net carbs” can be misleading for someone who is trying to lose weight. “Net carb” implies that dietary fiber and sugar alcohols in a product do not count. This may mislead dieters to believe that low-carb foods are low in calories, and may lead them into overeating… not taking into consideration the fat content of the product.

Net carbs can be confusing for someone who is trying to manage blood-sugar levels, especially for those who are dosing insulin requirements based on carbohydrate intake. To date, preprandial insulin-dosing guidelines are based on total carbohydrate intake, and more research is needed to determine the glycemic effect of sugar alcohols and fiber. Figure 2 shows how “net carbs” is the selling phrase for an ice cream product.

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Figure 2 Low net-carb product.

5. Carbohydrate-Modified Products Still Have Calories 

As mentioned above, a low-carb food does not mean low in calories. Manufacturers have become creative in lowering the carbohydrate contents of an original product. Examples include:

Figure 2 clearly shows the long list of ingredients in the low-carb product compared with the naturally made ice cream.

6. Fat Content Can Be High in a Low-Carb Food 

Cardiovascular disease is the leading cause of death among dialysis patients. Despite the very restrictive renal diet, it is very important to remind patients about a heart-healthy lifestyle, which includes a low saturated fats diet regimen. A product may be low in carbohydrates, but the fat may be >30% of the total calories. Normally, carbohydrates should be between 55% to 60% of the total calories. In Figure 2, the low-carb ice cream has 63% fat calories, whereas the regular ice cream has 42% fat calories.

7. Portion Control, Portion Sizes! 

The beauty of carbohydrate-counting is being able to adjust portion sizes to one's food preference. One of the tricks of manufacturers is altering the serving sizes of a regular product. Although Nabisco has pulled the Oreo CarbWell off the market, it remains a good example of serving-size alteration (Fig. 3).

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Figure 3 Is there a difference with nutrient content?

8. Being a Low-Carb “Junk” Food Does Not Free It From Being a “Junk” Food 

During the peak of launching low-carb products, Frito-Lay started manufacturing Doritos Edge and Tostitos Edge, each with a total of 6 net carbohydrates, 10 g of protein, and 3 g of fiber, boasting a 60% reduction of carbohydrates in both products. Frito-Lay even projected nearly $3 billion in combined sales in the United States annually.6 Several major manufacturers have retired their low-carb products, including Doritos Edge and Tostitos Edge. However, Internet sales of low-carb products are ongoing. The food item in Figure 4 has only fat and sodium… No other nutrient can be found.

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Figure 4 Low-carb “junk” food (from http://lowcarb4life.sugarbane.com/lowcarbsnacks.htm).

Ideally, listing food intake and an immediate analysis of “amounts” in the initial stage of diet lifestyle change can paint a clearer picture for patients. Basic information is the key: total carbohydrates affect blood glucose levels, and total calories affect weight management. Table 2 describes total intake if one decides to snack on the low-carb food items mentioned here.

Table 2. Low-Carb Snacking

	Snack items	CHO gm	FAT gm	Fat Calories	Calories
	2 sugar-free lemon cookies, 3 pcs	9	7	60	130
	1 cup low-carb ice cream	20	16	140	220
	Carb well oreo cookies, 2 pieces	16	5	45	100
	Cinnamuch pork puffs, 1-2.25 oz bag	2	7	56	101
	TOTAL	47	35	301	551

Our role as renal dietitians can be challenging when it comes to keeping up with food trends. It is also important to note that other than calories, carbohydrates, and fat content, repeated education regarding sodium and “hidden” phosphorus should be included in label-reading instructions. Occasional grocery store tours and giving explanations of different food labels are effective ways to educate our dialysis patients. Numerous low-carb items are still in the grocery shelves and online stores. Raising awareness in our patients will help them become “supermarket-savvy” and proactive in their own healthcare.