Walking Guide

Read This Before Starting a Low-Carb Diet

Danger, danger! Do alarm bells sound in your head at the sight of a carbohydrate-rich food? If eaten, do feelings of guilt and remorse swell up inside? Low-carb, slow-carb, no-carb…with the plethora of diets touting the evils of carbohydrates, it's no wonder that folks are petrified of potatoes and leery of anything that contains wheat. It's true that foods that contain carbohydrates are abundant in our society and it is easy to overindulge.
But guess what? Carbs can be your friend. In fact, eliminating them could actually be harmful to your long-term health, and you may be missing out on some of their slimming effects. Here's the catch, though: You must know which ones to forgo and which to welcome back on your plate.
Before you decide to embrace the carb-free way to be, get the facts on how carbohydrates affect your life and goals.

How Carbohydrates Actually Work

Not only are carbohydrates found in many foods—fruits, vegetables, beans, dairy products, foods made from grain products, sugar, honey, molasses, corn syrup—but they're also the body's ideal fuel for most functions. They supply the body with the energy needed for the proper functioning of the muscles, brain and central nervous system. In fact, the preferred source of energy for the human brain comes from carbs.
To create energy, carbohydrates go through a transformative digestion process:
  • The body converts digestible (non-fiber) carbohydrates into glucose. The glucose then enters the bloodstream. Insulin is secreted from the pancreas, which allows the glucose to enter the body's cells to be used as fuel. Some glucose is stored as glycogen in the liver and muscles for future use, like fueling a long workout. If there is extra glucose, the body will store it as fat.
  • The speed at which carbohydrate foods are digested and utilized by the body, as well as the increase in blood sugar level and insulin production, depends on many factors.  These factors include the following: the type and amount of carbohydrate eaten, the amount of fiber contained in the food, other foods that are eaten with the meal or snack, physical activity, stress and certain medical conditions.
Chemically speaking, there are three types of carbohydrates:
  1. Simple Carbohydrates are composed of one or two sugar units and are found in both natural (strawberries) and refined (white table sugar) forms.
  2. Complex Carbohydrates (also referred to as starch) are made up of many sugar units and are found in both natural (brown rice) and refined (white bread) forms.
  3. Non-Digestible Carbohydrates (also called fiber). The body is unable to breakdown fiber for absorption. As such, it is not an energy source for the body but does promote health in many other ways.

All Carbs Are Not Created Equal

Simple carbs, complex carbs and fiber are found in many foods. Some of these foods provide important nutrients that promote health; let's call these foods "smart carbs."  Others, "shoddy carbs," provide calories with little to no nutritional value.
Smart Carb Foods:
  • Fruits contain primarily simple carbohydrates but also valuable vitamins, minerals, fiber and water.
  • Vegetables contain varying amounts of simple and complex carbohydrates, vitamins, minerals, fiber and water.
  • Legumes such as beans, peas, soybeans, lentils and legumes contain complex carbohydrates, fiber, vitamins, minerals and protein.
  • Milk products such as fluid milk and yogurt contain simple carbohydrates along with protein, calcium and other nutrients.
  • Whole-grain products contain complex carbohydrates, fiber, vitamins, minerals and protein. The amounts vary depending on the type of grain used and the amount of processing.
Shoddy Carb Foods: 
  • Examples of calorie-containing sweeteners include white sugar, brown sugar, syrups, honey, and molasses. Sprinkling these added sugars into coffee or using them as a major ingredient in sweet treats and beverages can quickly add unwanted carbs and calories.
  • Refined-grain products contain complex carbohydrates, but much less fiber, vitamins and minerals when compared to their whole-grain form. The nutrient amounts vary depending on the type of grain used and the amount of processing.
  • French fries, breaded and fried vegetables, and potato chips are examples of over-processing that turns that nutrient-rich vegetable into a high-calorie, nutrient-lacking creation.

How the Body Responds to a Very Low-Carb Ketogenic Diet

When there is a severe deficit of carbohydrates, the body has several immediate reactions, one of which is that it starts using protein as a fuel source. Ketones, a by-product of incomplete fat breakdown, begin to accumulate in the blood. As a result, there is a loss of energy, as well as nausea, headaches, bad breath, dehydration and constipation. Long term usage can bring about nutrient deficiencies, malnutrition and increased risk for certain diseases such as heart disease, high blood pressure, cancers, diabetes, gout and kidney stones.
There are many "how's" that need to be explored before you decide if a low-carb diet is for you: How low will your carb intake be? For how low do you plan on sticking to the diet? How will it impact my other medical conditions? How happy will I be? SparkPeople's goal is to support members on their road to wellness. Our program sets the carbohydrate range to 45 to 65 percent of calories (50 percent for our diabetes program), numbers that are based on the Institute of Medicine Dietary Reference Intakes for carbohydrate. However, a member can change the carbohydrate range based on recommendations from one's health care providers, if needed.
The Million Dollar Question

How do you get the nutrient-boosting benefits from carbohydrates, while still losing weight? Use the three rules of the "KISS Me Plan": Keep It So Simple for Me for carbohydrate control.
Rule #1: Know which carbohydrate containing foods are "smart" and which are "shoddy."
Rule #2: For accuracy, weigh and measure all carbohydrate-containing foods using standard food portion sizes.
Rule #3: Include the correct number of carb-containing food servings in your eating plan.
Listed below are the food groups which contain carbohydrates, along with the suggested number of servings based on a 1,200 to 1,600 calorie plan for weight loss. Adjustments should be made for higher calorie ranges.

Smart Carbs:

Whole Grains and Starchy Vegetables: 4 to 5 servings daily (approximately 15 grams of carbohydrate/serving)
  • 1/2 cup corn, peas, potato, sweet potato
  • 1 small potato, sweet potato
  • 1/2 cup legumes, lentils, beans (black, garbanzo, kidney, lima, navy, pinto, soybean)
  • 1/2 cup cooked brown rice, whole-grain pasta, oatmeal
  • ¾ to 1 cup whole-grain cereal
  • 1 slice whole-wheat bread
  • 6 whole-grain crackers
  • 3 cups air-popped popcorn
Refined Grains: no more than 1 to 2 servings daily, preferably 0 servings (approximately 15 grams of carbohydrate/serving)
Keep in mind that this number counts toward the Whole Grains & Starchy Vegetables total for the day.
  • ½ cup cooked white rice, pasta, noodle
  • 1 small flour tortilla, muffin, roll
  • 1 piece of a thin crust, 12-inch pizza
  • ½ small bagel, hamburger or hotdog bun
  • ¾ to 1 cup refined grain cereal
  • 1 slice white bread
  • 6 crackers
  • 20 oyster crackers
Fruit: 2 to 3 servings daily (approximately 15 grams of carbohydrate/serving)
  • 1 small apple, banana, orange
  • ½ cup diced peaches, pears, pineapple, fruit cocktail—fresh, frozen, canned
  • 1 cup berries or cubed melon
  • 17 grapes
  • 2 tablespoons dried fruit
  • ½ cup 100% fruit juice (limit to no more than 1 serving daily)
Dairy: 1 to 2 servings daily (approximately 12 grams of carbohydrate/serving)
  • 1 cup low-fat, no added sugar yogurt
  • 1 cup skim or low-fat milk
Non-Starchy Vegetables: 3 to 7 servings daily (approximately 5 grams of carbohydrate/serving)
  • 1/2 cup cooked , 1 cup raw or 1 cup leafy greens
  • Asparagus, green beans, broccoli, Brussels sprouts, cabbage, carrots, cauliflower, celery, cucumber, eggplant, onions, greens, kohlrabi, mushrooms, pep pods, peppers, radishes, spinach, summer squash, tomatoes or turnips.
  • ½ cup 100% juice (limit to no more than 1 serving daily)
Shoddy Carbs: No more than 1 to 2 servings weekly (approximately 15-20 grams of carbohydrate/serving)
Food Portion Size Calories Carbohydrates (g)
Cookies, chocolate chip 2 medium 120 16
Chocolate candy kisses 6 133 17
Jelly beans 10   74 20
Fruit leather .75 ounce   75 17
Doughnut holes, glazed 3 165 19
Sugar-sweetened beverages, including soda,
fruit drinks, sweet tea, lemonade, sports drinks
6 ounces
(3/4 cup)
  76 19
Corn syrup, pancake syrup, jelly, jam
           preserves, molasses
4 teaspoons
3 teaspoons
4 teaspoons
French Fries 10 strips 166 20
Breaded mushrooms 3 ounces 190 19
Baked cheese crackers
1 ounce (16 chips)
1 ounce (4 twists)
1 ounce (25 crackers)
Beer 12 ounce 153 13

The bottom line here is that you should be working to cut down on added sugar and refined grains, but should still consider all other carbs fair game. It's time to let those smart carbs back on your plate as you achieve and maintain a healthier weight.

This article was updated by Becky Hand, August 2017.
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Member Comments

I think anyone that starts a low carb diet should meet with a dietian first and get some guidance first. Report
thanks Report
Thank you for the informative article. Report
There are a lot of things on SP that is out of date! Report
Not totally convinced this article is 100 percent accurate as fat is NO longer the villain it was in the 1980's nor is sugar (and carbs) the angel that they were portrayed- couldn't help but notice the SPIKE in obesity after the NO FAT diet "FOODS" decade - COINCIDENCE?? I doubt it .Ancel Keys and his shoddy SUGAR INDUSTRY FUNDED "research" has been largely debunked by a great deal of people. If low carb diets are so bad for you why are there any Inuit left? They should have died out generations ago!! Report
Not sure if I commented about this before or not, but this information is sadly out of date; the facts are not correct there IS science to back that statement up. I'm not sure why reality hasn't set in for more people, especially in the medical and nutritional fields.

More folks who posted before me made all the other points I'd make if I were to continue, so I'll just leave it at this.

Thanks for sharing Report
This is false:

"Long term usage can bring about nutrient deficiencies, malnutrition and increased risk for certain diseases such as heart disease, high blood pressure, cancers, diabetes, gout and kidney stones."

Not a good article, mostly rubbish. Report
Great information! Report
Excellent article, great need-to-know information, Very helpful, thanks! Report
Diabetes is caused by eating too many CARBS. Science not bunk. Read on to learn the truth.

I "am" diabetic. My A1C was 12.2 when diagnosed. I was put on Metformin and sent home with the tired old "Eat less / exercise more / lose weight / it's all your fault" nonsense. I tell you this because I was killing myself and the medical establishment was assisting my suicide (by Carbs) .

High blood glucose is a SYMPTOM of diabetes, it is not the disease itself. BEING FAT is a SYMPTOM of high blood glucose, but more importantly a symptom of HIGH INSULIN levels.

Diabetes is insulin resistance. Insulin resistance is CAUSED BY, in 98% of the cases, eating high levels of carbohydrates. Science not bunk. Here's the REAL DEAL...

1) When you eat sugar (and non-fiber carbs are just sugar to the body), that sugar gets into your blood stream within an hour. Insulin levels spike to cause the body to do something with that sugar. The cells of your body cannot deal with all that sugar, but the insulin is forcing the cells to take it in. Since the cells cannot use it, they turn it into fat for use at a later time.

So eating cookies, crackers, pies, cakes, potatoes, rice, pasta, pizza, breads etc. (the typical american diet) CAUSES BLOOD GLUCOSE SPIKES. Which CAUSES insulin to spike. This is a direct cause / effect relationship here. Science not bunk.

2) Now you eat more carbs a few hours later. You are advised to eat "six small meals a day" right? And the advice is to eat CARBS right? So a few hours later, while your blood glucose levels are still above normal, you eat MORE CARBS. Which gets in the blood immediately, causing insulin to spike, causing the sugar to get in the cells, which can't use it and so turn it into FAT.

Are we seeing a pattern here? Have you seen ANYTHING about the fat coming back out of the cells to be used by the body for energy? Nope! So you eat more carbs, more high insulin, more fat stored. Ad Nauseum day after day, week after week, year after year and soon you look like a FAT WALRUS lying on the beach. And gu... Report
Thank you for providing science based information, not just in this article, but in every one of yours I've read so far. I hope if enough people keep stating the facts, the myths will eventually be recognized for what they are. A girl can dream, right? Report
Um this article is false. I already got diabetes and high blood pressure from eating fruit, dairy, wheat and so on. Plus those foods cause bloating, the runs and allergens, leaky gut. Recommend a diet that actually works besides the carb and exercise diet Americans are doing and are falling with heart attacks every year. . If it worked we would all be skinny. It best to eat green in season and stay away from gmo modified fruits and plants with micro toxins on them. Fructose gets stored in the liver and cause fatty liver. A avocado has more health benefits then a banana. Just like cigarettes, too much sugar kills. Even with diabetes medicine you go blind, get your foot cut off and stroke. My body should run on my stomach fat., not insulin and sugar. And since we are made of fat, I say eat it!!! Report
Iím not sure what is right anymore. One says one thing, one says another. I do know that since Keto I am feeling better. I have no more than 20 g of carbs a day usually only about half that. I am now off my metformin for my sugar. My blood pressure is now under control and my cholesterol numbers are almost back where they need to be. The weight has came off. Maybe for once we needs facts and not opinions. Report
Great information. Thanks! Report
Walking Guide

About The Author

Becky Hand
Becky Hand
Becky is a registered and licensed dietitian with almost 20 years of experience. A certified health coach through the Cooper Institute with a master's degree in health education, she makes nutrition principles practical, easy-to-apply and fun. See all of Becky's articles.
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