Do carbs make you fat?
Despite what a lot of the latest diet books claim, carbohydrates (like pasta, bread, potatoes, and fruit) are not fattening in and of themselves. Excess calories (whether from carbohydrate, protein, fat, or alcohol) are converted to and stored as body fat in your body. The only way that carbohydrates can become fattening is 1) if you eat too many of them (too many calories from ANY source can be fattening) or 2) if you smother them with tons of high fat/high calorie sauces and spreads.
Read on to learn…
  • More about how carbs can make some people fat.
  • What's the difference between complex carbs and simple sugars.
  • Which type of carbs will maximize your energy, health, and fitness goals.
  • How to manage sugar cravings.
Why carbs make some people fat
There are two main reasons why carbohydrates can lead to weight gain in some people: 1) eating large portion sizes and 2) smothering them with large amounts of high calorie, high fat toppings.

1. Eating large portion sizes
Over the past several years, portion sizes of carbohydrate-rich foods have doubled or even tripled in restaurants. As a result, we have become accustomed to jumbo, deluxe, and super-sized portions whether we eat out or at home. Take a look at the calorie difference between recommended serving sizes of carbohydrate-rich foods and typical restaurant serving sizes.
Food Standard Serving Typical 1977 Colossal 2000
Pasta 1 oz. dry 
(½ cup cooked)
100 calories
2 oz. dry (1 cup cooked) 200 calories 6 oz. dry 
(3 cups cooked)
600 calories
Bagel 1 oz. 
(1/2 small bagel) 
90 calories
2-3 oz. 
(1 medium bagel)
225 calories
4-5 oz. 
(1 large bagel)
405 calories
Muffin 1 oz. small
100 calories
2 oz. medium 
200 calories
4-6 oz. large 
500 calories
Baked Potato 3-4 oz. small
103 calories
6-7 oz. medium
190 calories
16 oz. large
470 calories
French Fries About 10 fries
(1.3 oz.)
120 calories
About 30 fries 
(4 oz.)
360 calories
About 50 fries
(6.7 oz.)
600 calories
Nonfat Soft Serve
Frozen Yogurt
½ cup
110 calories
NA 1 pint
440 calories
Fruit Juice 6 oz. fruit juice
80 calories
NA 24 oz. fruit smoothie
430 calories
Cola NA 10 oz. bottle
125 calories
40-60 oz. fountain cup
480 calories
2. Smothering them with large amounts of high calorie, high fat toppings.
For every tablespoon of butter, margarine, or even “heart-healthy” olive oil you add to bread, potatoes, or pasta you’ve packed on an extra 100-120 calories. If you add ¼ cup of pesto or ½ cup of alfredo sauce, you’ve got 300 additional calories. 

To learn how to deal with super-sized portions and hidden fat calories when eating on (or off) campus, check out the section on overcoming real world challenges.

What is the purpose of carbohydrates?
Carbohydrates are the body’s preferred source of energy. Some of our cells (like our brain and red blood cells) can ONLY use carbohydrates for energy.

Because of their vital role, most of our daily calories should come from carbohydrates. 
But, the exact amount you personally need varies anywhere between 45 and 65% of total calories, depending on your individual health and fitness needs. For most active, healthy college students, 50-60% of total calories from carbohydrate is a reasonable goal. 

Who may benefit from eating less carbohydrate? Someone with diabetes or insulin resistance may enjoy better blood sugar and/or insulin control with an eating plan that is lower in carbohydrate (i.e. 45% of total calories). People with these conditions can't handle carbohydrate as well, especially if they are not physically active or they are obese. Click here for more info on diabetes and insulin resistance.

Who may benefit from eating more carbohydrate? Endurance athletes preparing for the LA marathon may train and compete better if they consume 65% of total calories from carbohydrate (or even up to 70% of total calories from carbohydrate a few days before the race if carbohydrate loading). A higher carbohydrate intake will help maximize their muscle carbohydrate (or glycogen) stores and, as a result, help increase their endurance. 

Types of carbohydrate: simple vs. complex
Carbohydrates can be classified into two general categories based on their chemical structure: simple carbohydrates (or sugars) and complex carbohydrates (or starches).

1. Simple carbohydrates (sugar)
Much of the sugar Americans consume comes from what is added to processed foods (such as cookies, cakes, muffins, ice cream, candies, breakfast cereals, sports bars, and especially sodas and fruit drinks). The most common form of added sugar is plain white table sugar (or sucrose). Other sugars that are added to foods include molasses, honey, high fructose corn syrup, and fruit juice concentrate. Read labels to identify these sources. 

Sugar is also naturally occurring in some foods. For example, fruit has fruit sugar (called fructose), and milk has milk sugar (called lactose). Just because these foods are high in sugar doesn't make them "bad" foods. On the contrary, these foods are loaded with important vitamins and minerals, and they are relatively low in calories. It's only when sugar is concentrated or extracted from natural sources and then added to nutrient-poor processed foods (like the foods mentioned above) that sugar can become a problem. 

2. Complex carbohydrates (starch)
Complex carbohydrates are in foods such as bread, cereal, rice, pasta, tortillas, crackers, pretzels, beans, and starchy vegetables (like potatoes, peas, corn, and yams). Because whole pieces of fruit have fiber (unlike fruit juices or fruit juice concentrate sweeteners), they too can be considered complex carbohydrates.

Much of the complex carbohydrate Americans consume comes from refined and processed products (such as white breads, white rice, white pasta, and white instant potatoes or French fries). The refinement of these foods takes away many of their nutrients and fiber and leaves just a white starchy final product. These foods are “enriched,” but only with five nutrients (four B vitamins and iron). All the other nutrients are forever lost.

Foods in their whole form (such as whole wheat bread, brown or wild rice, oats, and whole grain cereals) retain all of their nutrients and fiber. Click here for more info on carbohydrates and how to pick whole grains.

Does it matter which type of carbohydrate you choose?
All carbohydrates (whether simple or complex) are ultimately broken down in the body to the same thing: sugar (i.e. blood sugar or blood glucose). And all carbohydrates ultimately fuel your brain and body the same way. So does it matter whether carbohydrate fuel comes from a diet of mostly added sugars in gummy bears, Oreo cookies, and soda vs. a diet of mostly whole grains, beans, vegetables, and fruits? Absolutely! Here’s why…

1. Simple sugars when added to foods are a more concentrated form of carbohydrate and calories. Naturally occurring sugars in whole pieces of fruit, as well as complex carbohydrates in whole grains and vegetables, are diluted with fiber and water (which makes them more bulky so they fill you up without extra calories). 

1 Tbs. sugar provides 12 g carbohydrate and 48 calories
1 c. berries, which also provides 12 g carbohydrate and 48 calories.

Similarly, naturally occurring sugar in nonfat milk is diluted with water, protein, and many important vitamins and minerals.

2. Simple added sugars, as well as many refined, low fiber starchy foods, have few (if any) vitamins or minerals. They’re just “empty calories.” 

1 Tbs. sugar provides only 12 g carbohydrates and 48 calories.
1 c. berries provides 12 g carbohydrates, 48 calories PLUS 85 mg vitamin C, 26 mg folate, 247 mg potassium, and 3 g fiber. 

Calories from added sugars are hiding in many foods. Take a look at the calorie difference between foods that have a lot of hiding added sugar vs. foods that have no hiding added sugar:
Food Comparison Total Carbohydrate/Sugar Total Calories
Plain fat free yogurt with fresh berries (1 c.)
One brand* of fat free fruit- sweetened yogurt (1 c.)
*Not all brands have this much added sugar. Read your labels!
13 g -- all naturally occurring sugars

51 g -- 12 g naturally occuring sugars + 39 g (10 tsp.) added sugar
94 calories

250 calories
Water (12 oz.)
Cola beverage (12 oz.)
 0 g -- no added sugar
38 g -- 10 tsp. added sugar
0 calories

150 calories
3. Simple added sugars, as well as many refined, low fiber starchy foods, are digested and absorbed more quickly, resulting in a rapid increase in blood sugar levels. This gives you a rapid, immediate burst of energy. But, this energy is short lasting. High blood sugar levels trigger a rapid surge of the hormone insulin. Insulin causes a rapid drop in blood sugar, leaving you feeling tired, hungry, and craving more sugar shortly after you eat. 

Not everyone experiences these "highs" and "lows" as a result to eating simple, sugary, refined foods. But as many as one in four adults (without diabetes) may be at risk due to a genetic predisposition to insulin resistance. Insulin resistance can lead to increased insulin levels, increased sugar cravings, and increased risk for obesity, diabetes, and heart disease. Click here for more info on diabetes and insulin resistance and simple lifestyle choices you can make to maintain and/or achieve healthy blood sugar levels.

Is it normal to crave sugar?
Many students worry about having sugar cravings. They feel as if they are "bad" for craving sweet things. Keep in mind that it's actually very natural for all of us to crave sugar to some extent. As infants, we instinctively turn to our mother's breast to satisfy our innate craving for sweet milk. Sometimes, though, these cravings can get out of hand; and sweets begin replacing other nutrient-rich foods in the diet. If sugar cravings are becoming a problem for you, click here to learn some strategies for stopping sugar cravings.

Bottom Line
  • One of the good points about many of the popular low carbohydrate diets is that they draw attention to the quality of the carbohydrates that we’re eating. Most Americans are choosing lots of refined, sugary, calorie-rich (but nutrient-poor) carbohydrates like soda, candy, white bread products, white rice, and processed french fried potatoes.
  • A healthy eating plan consists of 45-65% of mostly high quality, wholesome carbohydrates (including whole wheat bread, brown or wild rice, oats and other whole grains, beans, vegetables, fruits, and low fat milk foods). Keep added sugars to no more than 10% of your total calories.
  • That doesn’t mean that it’s “bad” to eat sweets or processed foods once in a while or even every day. There are no “good” or “bad” foods. Balance is key.
  • For instance, white rice or white pasta is not “bad” if you’re eating it with high fiber vegetables and a good source of lean protein. The whole meal is rich in fiber. And, the protein and fat in the meal help slow down how fast the carbohydrate is digested and absorbed, so the result is a lower blood sugar and insulin response.
  • Further, if you’re active and spending many calories a day, you can enjoy some “empty calories” in your diet. It’s all about balance and moderation!

Sheri Barke, MPH, RD
COC, Student Health & Wellness Center
Rev. 2005