Diet trends come in waves, and the most recent low-carb frenzy was no exception. Enthusiasm for these diets may have waned (once again), because they don’t work in the long run. But there are still plenty of books and products out there, along with talk of “good” and “bad” carbs. What’s the deal with carbohydrates, and what role do they play in weight management? Here are some objective, scientifically-based facts.
Eating carbs won’t make you fat.
You won’t gain weight from eating carbohydrates unless you are taking in more than what your body can burn for daily activity. Some experts believe, however, that the type of carbohydrates that make up most of your diet might make a difference. The 2005 Dietary Reference Intake for carbohydrates recommends an intake of between 45%-65% of our daily calories.
The amount of weight lost on a low carb diet is deceptive.
When a person first begins a low carbohydrate diet, the initial weight loss can appear dramatic. But almost all of the lost weight is due to the release of water as the body burns glycogen. Also, if the total calorie intake is low enough, part of the weight reduction is from loss of muscle tissue.
Carbs keep us going.
Carbohydrates are the best energy source to keep our muscles moving and our brains functioning. Everyone needs “doses” of carbohydrates throughout the day, for emotional, intellectual and physical well-being. It is especially critical to fuel your body with a steady supply if: you exercise or participate in any type of athletics, you need to be mentally alert, and/or you live an active lifestyle. That’s most of us!
Your energy level will drop without enough carbs.
Our bodies store a limited supply of carbohydrates in the form of glycogen–in both the muscles, and liver. We draw on the muscle glycogen and some of our stored fat for daily energy, especially with exercise or physical labor. Fat can’t be used as the exclusive fuel, so when the carbohydrate reserve is depleted, we feel very fatigued.
Low carbs negatively affect thinking, performance.
The glycogen stored in the liver is used to help maintain a normal blood sugar level, to “feed” our brains. Unlike the muscles, the brain can’t store its own glucose or burn fat. So, when you overly-restrict carbohydrates to the point that you deplete your liver glycogen, the brain is poorly fueled. The result? Loss of coordination, inability to concentrate, lightheadedness and weakness.
Low carb diets are lacking in important nutrients.
Vitamin E, thiamin, calcium, iron, magnesium, potassium, and zinc come up short in low carbohydrate diets. When foods from plant sources are cut back, fiber and disease-fighting phytochemicals are also lost.
Carbohydrates affect your moods.
Carbohydrates help keep up the levels of serotonin in our brains. Serotonin is a chemical that produces a feeling of calm, improved mood and reduced appetite. Some people are especially sensitive to serotonin levels, so when they cut back on carbohydrates and their levels drop, they start to feel depressed or worsen their existing depression. Others find themselves feeling nervous, short-tempered and/or moody.
On the other hand, if you binge on a lot of high carbohydrate foods at one sitting, sluggishness and grogginess can result. It’s best to eat moderate amounts of carbohydrates throughout the day, to maintain even moods and keep energy levels up.
Eating, digestive and weight problems can result when carbs are reduced too much.
Without enough carbohydrates, the diet is lacking in fiber. Fiber is needed to prevent constipation, and it also slows the digestion of foods and therefore lowers their glycemic load. Fiber also may help prevent overeating because it contributes to a sense of fullness. As a bonus, there is some evidence that fiber reduces the risk of a number of diseases.
Unrelated to fiber, when carbohydrates and calories are severely restricted, a condition called gastric paresis may result. The stomach loses its motility (ability to move). It becomes hard for food to pass through it, so eating becomes difficult. In addition to nausea, vomiting and abdominal bloating, serious consequences such as malnutrition can result.
Low-carb foods aren’t always low in calories.
Look around the grocery store as well as some restaurants, and it’s clear that low carbohydrate foods are the latest craze. The truth is that the FDA has no definition for low-carb foods, and any food can be so labeled. As a result, some manufacturers use labeling tricks to disguise a food’s actual carbohydrate content. For other low-carb offerings, the calorie content is often the same as its regular counterpart, because of added protein and fat. Be aware of this before you plunk down up to four times more money for a so-called low-carb food.
ALL carbs are broken down to sugar.
Carbohydrates are found in a broad range of foods, including fruits, vegetables, grains, starches, milk and of course sweets. Some are called complex carbohydrates. Due to their molecular structure, it takes more work for the body to break them down into sugars. On the other hand, simple sugars are just what the name implies; easy for the body to digest, due to their less complicated structures.
Carbs have differing effects on blood sugar.
Scientists have learned that the impact of carbohydrates on our blood sugar levels is not just a matter of whether they are complex or simple. How fast a food enters the blood stream and raises blood glucose (sugar) levels is called its glycemic load.
Eating too many high-glycemic foods may increase health risks.
These foods are quickly digested and flood your bloodstream with a lot of sugar all at once. The pancreas in turn releases a large amount of insulin to clear the blood stream of the excessive sugar. The problem is, there is a rebound effect, tipping blood sugar levels back to the low side. When your blood sugar level drops too low soon after a meal, you’re going to get hungry again and are apt to overeat.
Some scientists are concerned that a diet packed with high glycemic load foods may contribute to weight gain and obesity. Also, some researchers are theorizing it may possibly cause body cells to become resistant to insulin, as well as wear down the pancreas. If so, this would increase the chances of developing Type II diabetes. Other researchers don’t agree, and believe any weight gain is simply due to excess calories in any form, and it’s the resulting excess body fat that leads to insulin resistance and Type II diabetes.
The following foods have a high glycemic load:
- Sugar, soft drinks and honey
- Crackers, white bread and refined cereals
- French fries, white rice and other potatoes
In general, foods with a low glycemic load are healthier.
These foods cause a gradual rise in blood sugar, which helps sustain you until the next meal. You’ll feel better because you are provided with a steady supply of fuel, and you’re therefore less likely to experience mood swings. You’re also less apt to overeat and gain unwanted pounds.
In general, foods with a low glycemic load are less processed or refined. If it’s a starchy food, the less water it absorbs when cooked and the less swollen it becomes, the better. This is why sweet potatoes and pasta (especially al dente cooked) have less of a glycemic response than other starches.
The following foods have a low glycemic load, and are the best sources of carbs:
- Whole fruits
- Whole wheat products
- Oatmeal and whole grain cereals
- Brown rice and barley
- Bran and bulgur wheat
Don’t become compulsive about the glycemic load of foods.
There are many other high carbohydrate foods that aren’t listed here. Some fall in the middle of the glycemic rankings, while others haven’t been studied yet.
There are many factors that can affect the glycemic load of a food, including the amount of fat and protein eaten with it, how the food was prepared, the portion size and the fiber content. This is still an emerging area of research, with a lot more to learn. Scientists aren’t telling people to eliminate high-glycemic foods, but to be aware and more cautious of amounts. And, we know that the low-glycemic foods are high in fiber, nutrients and phytochemicals, so we can’t go wrong in striving to include more of those foods.
The bottom line?
It still comes down to the same old advice: try to eat more whole grains, vegetables and fruits–and less of the sweets, processed and refined foods. Don’t freak out if you can’t, but slowly move in this direction for best health.