Friday, May 26, 2017

Nutrition Label Errors

Nutrition labels are good for knowing how much carbohydrate is in the processed food you eat, if you eat any. Unfortunately whole foods don't come with nutritional labels.

But I've always considered the labels as approximations rather than exact numbers. They'll tell you, for example, that there's more protein than fat or whatever in some food, but they won't really tell you the exact amounts.

There are several reasons for this. First, they round the numbers off. So 3.49 grams would be listed as 3 grams and 3.5 grams would be listed as 4.

Second, they don't have to include anything with less than 5 calories or 0.5 grams. And this pertains to the serving size. So if you ate 4 servings, you could have a lot more of something than you thought.

Third, the manufacturers don't analyze every package they sell. One estimate was $750 per analysis in 1997, a lot for a loaf of bread, although they can also us nutritional tables to estimate the totals.

Finally, the nutritional content of the ingredients used to make the product can change from batch to batch and the manufacturer can't control that.

So overall, the labels are useful but not exact.

I recently came across a label that was just plain wrong. It was a sausage product and listed the ingredients as pork, water, wheat rusk, and salt and spices. So pork was the first ingredient (manufacturers are required to list ingredients according to amounts) but the label said it had no protein, as well as no carbohydrate. Huh? Pork is mostly protein and fat and rusk is mostly carbohydrate.

I telephoned the company and asked if maybe they just used pork fat and was told yes. Then I went back to the label and saw that it said one link had 150 calories, of which 50 calories were from fat. So what were the other 100 calories from. The water?

I called the company back, and now they admitted that the label was wrong. The sausage contained 4 g of carbohydrate and 19 g of protein. That totaled 146 calories, or 150 rounded up.

But what if someone used the carbohydrate and protein content to calculate bolus insulin. The calculated insulin would be incorrect, and they'd go higher than expected.

So that's yet-another reason it's so difficult for people who inject bolus insulin to keep their blood glucose levels level. I wonder how many other labels contain similar errors.

What this means is if you see a label that seems odd, don't assume it's correct. First check the numbers. Multiply grams of carbohydrate and protein by 4 and grams of fat by 9 to get calories. If they don't add up, call the company to find out. In someone without diabetes, thinking you were eating a little less carbohydrate and protein would not cause much harm. But when you're injecting bolus insulin, it could.

And because of rounding off, always take labels with a grain of salt.

Furthermore, remember that you can't always believe what someone who answers the telephone tells you. They could know about the issue, or they might not. In a large company, it sometimes pays to call twice to see if two different people have the same response.

Good control requires constant vigilance, but it's worth it in the long run.

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