Low carb diets are here to stay. There is no question that they can be very effective for fat loss when done correctly. But low-carb diets aren’t easy for those used to eating a lot of carbs. You must strictly limit the amount of carbohydrates you eat to get results. It’s not unusual for a low carb dieter to find themselves looking longingly at a piece of bread or cake!
But here comes nutrition and supplement science to the rescue in the form of No Impact Carbs, Net Carbs, and Effective Carbs with the promise of low-carb foods wrapped in traditionally high-carb packets! Sounds like a dream come true for low-carb dieters who crave the taste of carb-containing foods, but still want the results of a low-carb diet.
These terms are the latest buzzwords in the weight loss industry, but are people getting more than they bargained for with foods and supplements that are net carb based, no impact, and effective? Could these designer foods slow or even halt your progress on a low-carb diet?
Let’s start with some Nutrition 101. A carbohydrate is a nutrient your body uses for energy. It contains 4 kilocalories of energy per gram (kilocalorie is the formal name for calorie).
Your body converts the carbohydrates you eat into glucose/blood sugar for use in a wide variety of metabolic processes. This conversion can occur quickly or slowly depending on the type of carbohydrate food eaten. This rate is known as the glycemic index. A higher number means that the food is quickly converted to glucose; a lower number means the food is more slowly converted to glucose. For example, table sugar has a high glycemic index, while beans have a low glycemic index.
Generally speaking, a slower conversion of carbohydrates into blood sugar is better. This is why…
The faster food converts to blood sugar, the faster blood sugar levels rise. When blood sugar levels are high, your body secretes insulin, its main storage hormone. When insulin is present in the bloodstream, energy nutrients such as fats or carbohydrates are much more likely to be stored rather than burned. In terms of fat loss, this means that fat is not easily mobilized from fat cells and fat burning slows or even stops.
By controlling insulin secretion, you can effectively improve your body’s ability to mobilize fat from fat cells. Once they are mobilized from fat cells, they are more easily burned for energy, i.e. fat is lost. This is the basic premise that most low-carb diets are based on (there are exceptions, namely ketogenic diets, which I’ll get to later in this article).
Non-Impact Carbs:
No-impact carbs, simply put, are carbs that have very little effect on blood sugar levels when eaten. Since they don’t have an impact on blood sugar levels, they’re technically “allowed” on most low-carb diets.
Examples of no-impact carbohydrates you’ll see in low-carb foods and supplements include fiber, sorbitol, maltitol, and glycerol. Fiber is completely indigestible by the body and passes without being used. Sorbitol, maltitol, and glycerol are what are known as “sugar alcohols.” They are digested by the body but have little or no effect on blood sugar levels.
Effective carbohydrates:
Effective carbohydrate is the opposite of non-impact carbohydrate. They are carbohydrates that will have an effect on blood sugar levels. In most low-carb diets, the idea is to put a limit on effective carbs to keep blood sugar, and therefore insulin levels, in check. On a strict low-carb diet, this number can be as low as 20 grams of effective carbohydrates per day.
Effective carbohydrates can be divided into two basic groups: simple and complex carbohydrates. The body quickly converts simple carbohydrates to glucose, while complex carbohydrates (which, as the name implies, have a more complex structure) generally take longer to convert to glucose.
Net Carbs:
The net carb count is basically the same as the effective carb count. It is the total amount of carbohydrates in the meal minus the non-impact carbohydrates. These terms can actually be used interchangeably, which can be a source of confusion for consumers.
For example, if a food contains 30 grams of carbohydrates and 10 of those carbohydrates are fiber, the food contains 20 grams of net carbohydrates. It’s basically what’s left after subtracting everything else.
The term “net carbs” was coined by supplement manufacturers after the FDA reclassified glycerol (the aforementioned non-impact sugar alcohol) as a carbohydrate. Previously, it had not been classified as a carbohydrate or fat, and supplement manufacturers could use it as a sweetener without increasing the amount of carbohydrate in a protein bar. When this reclassification took place, the carb count of low carb protein bars increased dramatically! The term “Net Carbs” is a result of manufacturers wanting to maintain their carb counts while using glycerol in the manufacturing process.
The positive:
1. Non-impact carbs are very effective at reducing the insulin response you get from eating foods made from them. This means insulin levels will stay more even throughout the day, which will definitely improve your body’s ability to burn fat.
2. No-Impact Carbs help low-carb dieters stick to their diets. There’s no denying that sometimes you just want to eat a cookie. By eating a low carb cookie, you enjoy the cookie while keeping your insulin levels in check.
3. Low-carb foods are actually being used by people who aren’t on strict low-carb diets but just want to reduce their carb intake. Non-impact carbs are very effective for this purpose.
The low:
1. While non-impact carbs don’t affect blood sugar levels, they still contain calories (except for fiber, which is indigestible). A person who eats a large amount of non-impact carbohydrate-containing foods still gets all of their calories from an equivalent amount of regular carbohydrates! This fact is never highlighted in the advertising of non-impact carbohydrate foods. Total caloric intake is still important on low-carb diets. If your body is getting too many calories, it won’t need to burn body fat.
2. If you eat large amounts (or in some people, even small amounts) of sugar alcohols, you could experience what might tactfully be called “green apple fast steps,” ie diarrhea. Sugar alcohols are not normally found in large amounts in natural foods and may be difficult for the body to digest. What the body has trouble digesting, it tends to get rid of as quickly as possible (if you’re familiar with the results of eating Olestra, the fake fat, you’ll understand what I’m talking about).
3. If you are on a low-carb diet that is designed to put the body into ketosis (a state in which the body burns ketones for energy instead of blood glucose), eating carbs without impact may throw the body off. of ketosis by providing calories similar to carbohydrates. In this case, no-impact carbs basically defeat the entire purpose of the low-carb diet. If you are following a ketogenic diet, stay away from foods that have non-impact carbohydrates, as they will have an impact on your diet.
4. The FDA has not formally defined the terms “low carb,” “no impact carbs,” and “net carbs” as it has terms related to the fat content of foods. That will surely come, but in the meantime, many foods that aren’t particularly low-carb can get away with being labeled low-carb. As always, reading the nutrition information on the package and writing down serving sizes is your best protection.
Is the recent spate of low-carb foods on the market here to stay? Big food manufacturers rely on it, as evidenced by the recent Low-Carb Summit in Denver attended by many major companies such as Con-Agra and WalMart.
However, in my opinion, the burning question when it comes to low-carb foods is: are we getting away from the real point of low-carb? Processed foods are what got us into the obesity epidemic we find ourselves in today.
Is substituting one type of processed and manufactured food for another type of processed and manufactured food (albeit a “healthier” one) the way to go or would it be better to focus on less processed and naturally low-calorie foods? carbs?
The answer lies in how you choose to approach your low carb diet. Foods that contain “no impact carbs” can certainly be helpful from time to time, but I don’t think it’s wise to rely on them for a significant portion of your food intake. If you rely too much on no-impact carb foods, you may not lose or even gain weight in your diet!