Monday, February 28, 2011

Can Eating Too Few Calories Stall Your Metabolism?

Learn why cutting out too many calories can keep you from losing weight.

Medically reviewed by Christine Wilmsen Craig, MD
 
If you're like most people who want to lose weight, you want to lose it fast. So you may be tempted to make drastic changes in your diet to dramatically reduce the number of calories you consume. But what you may not know is that eating too few calories can actually backfire and sabotage your weight-loss efforts.
"It would make sense to stop eating [when you are trying to lose weight], but it actually works in the opposite way," says Kimberly Lummus, MS, RD, Texas Dietetic Association media representative and public relations coordinator at the Austin Dietetic Association in Austin, Texas.

Calories and Your Health

The most effective way to lose weight is to consume fewer calories than you expend, creating a calorie deficit. But if your calorie intake dips too low, says Lummus, your body could go into starvation mode. "Your body will start to store fat because it thinks it is not going to get anything," says Lummus. "You will be at a point where your body is kind of at a standstill."

Lummus says that when your body goes into starvation mode, your metabolism slows to a crawl, burning calories as slowly as possible to conserve its energy stores. This is why people who cut their calories too much may reach a plateau and stop losing weight.

Eating too few calories can be the start of a vicious cycle that causes diet distress. When you cut your calories so low that your metabolism slows and you stop losing weight, you probably will become frustrated that your efforts are not paying off. This can lead you to overeat and ultimately gain weight.

"It is so hard to sustain cutting calories and eating too little. What typically happens is that the person will go in the opposite direction; they will just become too hungry and go into a binging mode," says Lummus. "Because you are getting frustrated by not seeing any weight loss, you just sort of throw in the towel."

In addition to sabotaging your weight-loss efforts, eating too few calories can also harm your health. When your body goes into starvation mode, you are at increased risk for the following:
  • Abnormally low blood pressure and slow heart rate
  • Heart rhythm abnormalities
  • Electrolyte imbalances, especially potassium deficiency
  • Gallstones
  • Hair loss
  • Brittle fingernails
  • Loss of menstrual periods in women
  • Soft hair growth over entire body
  • Dizziness
  • Trouble concentrating
  • Anemia
  • Swelling in your joints
  • Brittle bones
  • Depression
Coming to Terms With Calories

Remember that calories are not your enemy. They are a vital part of a healthy and energetic life. "Your body needs a certain amount of calories just to sustain proper function," says Lummus. This is why fad diets that force you to cut out too many calories leave you feeling lethargic, shaky, and ready to give up.

Instead of opting for a fad diet, find a reasonable eating and exercise plan that allows you to lose one-half to two pounds per week. There is evidence that people who lose weight at this rate — by making better nutrition choices, eating smaller portion sizes, and exercising — also have the best chance of keeping it off. Make a plan to adopt new healthful habits that you will be able to stick to indefinitely, and always allow yourself a little wiggle room for special occasions.

Best and Worst Snacks

Eight not-so-healthy snacks, plus 8 easy, healthy alternatives.
By Elaine Magee, MPH, RD
WebMD Expert Column
What makes a healthy snack? A good-for-you snack is one that's high in nutritional value (protein, vitamins, minerals, fiber) but relatively low in calories, total fat, saturated fat (no trans fat), sugar, and sodium.  And the most important part of that equation is "high in nutritional value." Nuts, for example, are high in fat and calories -- but are also loaded with nutrients we need, which makes them a healthy snack.
On the flip side, not-so-healthy snack choices are usually low in nutritional value but high in calories, total fat, saturated fat (and sometimes trans fat), sugars, or sodium.
While fresh veggies and fruits make super-healthy snacks, those items aren't always convenient (or the top choices for your typical family). That said, here are some of the worst snack choices you can find in your local supermarket in terms of healthfulness -- along with some healthy alternatives you can buy or put together in minutes.
8 Not-So-Healthy Snacks
1. Chocolate Coated Donuts, Mini Donuts, and Snack Cakes
This is not to say that powdered-sugar donuts are good snack choices. But chocolate-coated donuts and snack cakes have even more saturated fat than other types. 

 
Calories
Total Fat (g)
Saturated
Fat (g)
Sugar (g)
Sodium (mg)
Entenmann's Pop'ems Frosted Donuts, 2 pieces
340
25
16
17
180
Hostess Ho Hos, 3 cakes 
370
17
13
42
220
Little Debbie Zebra Cakes, 2 
320
14
8
32
150
Hostess Donettes Frosted Mini Donuts, 3 donettes 
220
13
9
13
160

  
2. Snack Pies
The Safeway fruit pies even say "great snack!" on the package. This makes sense only if by "great snack," they mean high in calories, total fat, saturated fat, and sugar, and low in protein, fiber, and other healthy nutrients.

 
Calories
Total Fat (g)
Saturated
Fat (g)
Sugar (g)
Sodium (mg)
Safeway Berry Fruit Pie, 1 
450
24
13
13
370
Hostess Fruit Pies, 1 
480-520
20-21
11
29-33
400


3. Mega-Butter or "Movie Theatre" Microwave Popcorn
This is one of the few products that still contain trans fat. Just 3 tablespoons of unpopped popcorn (which ends up being about 3.5 cups popped) contains 4-5 grams of trans fat. It's easy to end up eating twice that amount, which can be 8-10 grams of trans fat and 24 grams of total fat. 

 
Calories
Total
Fat (g)
Saturated
Fat (g)
Trans Fat (g)
Sodium (mg)
Pop-Secret Extra Butter, 3T unpopped
190
12
2.5
5
300
Jolly Time Blast  O Butter, 2T unpopped
150
12
3
4
340

        
4. Lunchables (Snack Size) by Oscar Mayer
Two types of these snack-sized Lunchables contain about half a day's worth of the suggested amounts of fat, saturated fat, and sodium for someone eating around 2,000 calories a day.

 
Calories
Total
Fat (g)
Saturated
Fat (g)
Sugar (g)
Sodium (mg)
Bologna & American Cracker Stackers
390
22
9
11
900
Ham & Cheddar with Crackers
340
19
9
6
1,110


5. Regular Chips and Cheetos
Although the serving size listed on the package is 1 ounce, most of us snack on twice this amount. So that's what I'm using as the portion size. 

 
Calories
Total
Fat (g)
Saturated
Fat (g)
Trans Fat (g)
Sodium (mg)
Cheetos Puffs, 2 ounces 
320
20
4
0
700
Ruffles Cheddar & Sour Cream, 2 ounces
320
22
3
0
460
Cheetos Crunchy Wild Habanero, 2 ounces
300
22
3
0
480


6. Packaged Frozen Snacks
They sure seem convenient, but the calorie and saturated fat cost is high. You'd be hard-pressed to find packaged frozen products that are low in sodium and made with whole grains and smart fats. In this product category, it's buyer beware!

 
Calories
Total
Fat (g)
Saturated
Fat (g)
Trans Fat (g)
Sodium (mg)
Jimmy Dean Biscuit Bacon, Egg, & Cheese, 1 sandwich
330
20
7
3
760
Hot Pockets -- Pepperoni, 1 piece
340
17
8
0
730
Ore-Ida Easy Fries Golden Crinkles, 6-ounce box 
360
16
3
0
800
Toaster Strudel, 1 pastry
210
9
3.5
1
210


7. Tyson Fun Nuggets
They may seem like a good snack choice because they're high in protein (14 grams). But there are ways to get your protein without all the extra fat, saturated fat and sodium.

 
Calories
Total
Fat (g)
Saturated
Fat (g)
Trans Fat (g)
Sodium (mg)
Tyson Fun Nuggets, 5 pieces 
280
18
4
0
490

 
8. Cheese Crackers
One serving (1 ounce) probably won't fill you up, since cheese crackers are low in water, volume, protein and fiber. So you’ll probably double the serving -- which means your snack now contains 300 calories, 18 or so grams of fat, 6 grams of saturated fat and 500 milligrams sodium. 

 
Calories
Total
Fat (g)
Saturated
Fat (g)
Trans Fat (g)
Sodium (mg)
Ritz Bits made with cheese, 1 oz
150
9
3
0
250
Cheez-It Baked Snack Crackers, 1 oz 
150
8
2
0
250


8 Healthy Snacks to Try Instead
1. Toasted 100% Whole-Wheat English Muffin with Peanut Butter
You'll find at least two brands of 100% whole-wheat English muffin (Oroweat and Thomas) in most supermarkets. Toasted and spread with some natural-style peanut butter (the type that just contains peanuts and a little salt), these make a satisfying snack with 10 grams protein and 5 grams of fiber.

 
Calories
Total
Fat (g)
Saturated
Fat (g)
Fiber (g)
Sodium (mg)
Oroweat 100% Whole-Wheat English Muffin + 1 Tablespoon Natural-Style Peanut Butter
250
10
1.2
5
295

  
2. Planters Nut*rition Nut Mixes (or similar)
Don’t let the 15 grams of fat per serving fool you. Most of these fat grams are from beneficial monounsaturated fats (8 to 9 grams) and polyunsaturated fats (3 to 5 grams). Each ounce also contains at least 5 grams of protein and plenty of healthful phytochemicals like phytosterols and lignans.

 
Calories
Total
Fat (g)
Saturated
Fat (g)
Fiber (g)
Sodium (mg)
Planters Nut*rition South Beach Diet Mix, 1 ounce
170
15
2
2
50
Planters Nut*rition Heart Healthy Mix, 1 ounce
170
15
1.5
3
50


3. 94% Fat-Free Microwave Popcorn
When you're craving something crunchy, microwave popcorn can be a quick and easy snack solution. There are now some lighter options on the shelves. Even if you double the serving size listed on the label, it still only adds up to 240 calories, 4 grams fat, and 1 gram of saturated fat -- along with 8 grams of fiber.

 
Calories
Total
Fat (g)
Saturated
Fat (g)
Fiber (g)
Sodium (mg)
Orville Redenbacher's Smart Pop 94% Fat Free Butter, 3 TB unpopped
120
2
0.5
4
240


4. Quick Microwave Nachos (Baked chips with beans and cheese)
This high-protein snack (14 grams) is easy to put together. Just put an ounce of baked tortilla chips in a microwave-safe bowl and dot the top with small spoonfuls of the refried beans, right out of the can. Sprinkle some hot sauce or salsa over the top, along with a little shredded cheese. Pop in microwave for 30 seconds or so to heat the beans and melt the cheese. Jazz it up by adding chopped tomato, green onions, and a dollop of fat-free sour cream if you like.

 
Calories
Total
Fat (g)
Saturated
Fat (g)
Fiber (g)
Sodium (mg)
Baked Tostitos, 1 ounce, with 1/3-cup Fat-Free Refried Beans + 1 ounce Reduced-Fat Cheese
290
9
4
7
690


5. Quesadillas
A quesadilla is quick to fix in the microwave or over the stove. If you use a whole-wheat or whole-grain tortilla and reduced-fat cheese, you'll get plenty of protein and fiber (12 grams protein; 8 grams fiber) for hunger-satisfying power. You can customize your quesadilla by adding nutrient-rich vegetables such as tomatoes, chopped green onions, peppers, or avocado.

 
Calories
Total
Fat (g)
Saturated
Fat (g)
Fiber (g)
Sodium (mg)
100 Calorie 100% Whole-wheat Tortilla, 1 oz. Shredded Reduced-Fat Cheddar or Jack Cheese
190
7.5
3.5
8
560


6. Lower-Sugar Snack Bars
There are lots of types of snack bars out there, from bars made with granola or nuts or coated in chocolate or yogurt. Most contain plenty of sugar (usually about 12 grams), but there are a few (with 6 grams of sugar per bar) that dare to emphasize nuts instead of sweetness. Note that the grams of fat will be high due to the heart-smart fats found in the nuts.

 
Calories
Total
Fat (g)
Saturated
Fat (g)
Fiber (g)
Sodium (mg)
Nature Valley Almond Crunch Bar  
190
13
1.5
2
180


7. Fun-to-Eat Frozen Vegetables
Vegetables can be fun to eat, like frozen edamame (green soybeans) from the pod. Just heat in the microwave (you can also serve them cold), open up the pods and snack away at the green soybeans inside. They're low in calories and packed with fiber and protein (8 grams fiber, 10 grams protein). If you're hankering for a potato-based snack, the frozen steak fries are usually the lowest in calories, fat, and saturated fat because they have a higher ratio of potato to crispy exterior.

 
Calories
Total
Fat (g)
Saturated
Fat (g)
Fiber (g)
Sodium (mg)
Edamame (in pod), 1 1/8 cup
90
2
0
8
30
Ore*Ida Steak Fries, 3 oz
110
3
1.5
2
300


8. Yogurt and Fruit Smoothie or Parfait
In just a few minutes, you can transform yogurt and fruit into a tasty parfait or smoothie. For a smoothie, combine 1/2 cup plain or vanilla yogurt  with 1/4 cup frozen berries or other fruit, half a banana (if desired), 1/8 teaspoon vanilla extract, and a pinch of cinnamon in a blender until smooth. Add crushed ice if you want. For a parfait, combine the yogurt, vanilla and cinnamon, then layer the mixture with some frozen fruit.

 
Calories
Total
Fat (g)
Saturated
Fat (g)
Fiber (g)
Sodium (mg)
Plain yogurt (1/2 cup) and frozen fruit (1/4 cup) and 1/2 banana
145
2
1
3
80