More Can Be Less

[Guest guest]

I saw this on New York Times online today. I thought some of you

would appreciate it.

Peace,

With Fruits and Vegetables, More Can Be Less

By JANE E. BRODY

What determines how much we eat and how much we weigh? Is it the

amount of fat in foods, the presence of carbohydrates, the size of

our portions, what we drink with our meals, that elusive trait called

willpower? Conflicting popular advice can prompt would-be dieters to

give up before they even start.

The good news based on solid research is that you can eat more -

probably more food than you're now eating - and weigh less, if you

choose more of the right kinds of foods.

At a recent meeting on the worldwide obesity epidemic, important

insights into successful weight management were offered by Dr.

Barbara J. Rolls, a professor of behavioral health at Penn State. She

began her presentation on weight control with this irrefutable

statement:

" Calories count, no matter what you read in the press. The laws of

thermodynamics have not been reversed. "

With respect to weight gain and loss, the laws of thermodynamics can

be translated as: Calories consumed must be used or they will be

stored as body fat. The body does not waste energy, no matter what

its source. When people are placed on carefully controlled calorie-

restricted diets, the amount of fat in the diet - whether 25 percent

or 45 percent of calories - has little effect on weight loss, Dr.

Rolls reported.

People who claim that they can eat as much as they want (of protein

and fat, for example) and lose weight as long as they avoid certain

kinds of foods (carbohydrates, for example) are really eating less

(that is, fewer calories) than they did before.

But what about a majority of people concerned about weight control

who are not interested in cutting out breads, cereals, grapes,

bananas, watermelon, carrots, beets, potatoes, rice and pasta (not to

mention wine, beer, cakes, cookies, ice cream and other carbohydrate-

rich foods banned on Atkins-style diets)? Are they doomed to

remaining hopelessly overweight?

Not according to Dr. Rolls, an expert on satiety and satiation, words

that refer to what and how much a person has to eat at a meal to feel

satisfied and stop eating. Many characteristics of foods affect

satiety: how they look, taste and feel in the mouth; how much chewing

they require; the nutrients they contain; how densely packed the

calories are, and, independent of caloric density, the volume of food

consumed.

She does not dispute the popular premise that the " macronutrients " in

foods - protein, fat, carbohydrates, alcohol and fiber - influence

caloric intake and use. For example, calorie for calorie, protein

appears to be the most satiating nutrient. Furthermore, during

overeating, the body burns more calories to metabolize protein and

carbohydrates than it does when processing fats, which are the

nutrients most efficiently stored as body fat.

Food Volume Counts

So what makes your body say you've eaten enough? Dr. Rolls's studies

on satiety have clearly demonstrated an overriding influence of food

volume, prompting her to write an excellent book, " The Volumetrics

Weight-Control Plan: Feel Full on Fewer Calories " (Harper,

2000) with A. Barnett.

She found that the amount of calories in a given volume of food makes

a big difference in how many calories people consume at a given meal,

and throughout the day.

In nutritional parlance, this is called the energy density of the

food.

The greater the energy density - the more calories packed into a

given weight or volume of food - the easier it is to overeat.

" People tend to eat a consistent weight of food, " Dr. Rolls has

found. When consuming a calorie-dense food high in fat, people are

likely to eat more calories just to get in a satisfying amount of

food.

What increases food volume without adding calories? You guessed it.

Water. And what foods naturally contain the most water? You got that

right too. Fruits and vegetables.

" People given the message to eat more fruits and vegetables lost

significantly more weight than those told to eat less fat, " Dr. Rolls

said. " Advice to eat more is a lot more effective than advice to eat

less. Positive messages about what can be eaten are more effective

than restrictive messages about what not to eat. "

" Water has the biggest impact on the amount of food we eat, " she told

an international symposium on the obesity epidemic held recently in

Minneapolis. " Foods with a low moisture content increase the number

of calories people eat. "

What would fill you up faster - a quarter cup of raisins or one and

three-quarters cups of grapes? Raisins are simply dried grapes; both

contain the same macronutrients and supply the same 110 calories. The

difference lies in volume - the amount of water they contain. If you

ate a 475-calorie meal of soup, vegetables and fruit, you'd consume

twice as much food by volume than if you chose drier, higher fat

foods.

In her studies, people ate a constant weight of food, but if water

contributed significantly to the weight and volume of the food, they

ate about a third fewer calories. In one study, Dr. Rolls and

colleagues tested the amount people ate when offered a 270-calorie

chicken-and-rice casserole with a glass a water to drink, as opposed

to the same ingredients prepared as a soup. The soup eaters

spontaneously consumed 100 fewer calories, she reported.

In other studies, when participants were given a water-rich first

course - soup or a salad, for example - before their main dish, they

ate significantly fewer total calories than they did if the main

course was given without the low-energy-density appetizer. In

addition, study participants given foods containing lots of water and

fiber ate less throughout the day.

Thus, by decreasing the energy density of foods, people naturally eat

less, not just at an individual meal but all day long, Dr. Rolls

reported. This was true of lean and obese participants in the study.

After water, which has zero calories, fiber contributes the most to

food volume for the fewest number of calories. Fiber supplies 1.5 to

2.5 calories per gram, far fewer than fat, at 9 calories, or protein

and carbohydrates, at 4 calories per gram. Also, fiber holds water in

the digestive tract, which contributes to a more lasting sense of

fullness.

Fiber is found only in plant foods: fruits, vegetables and grains,

especially whole grains. Along with water, it acts as a digestive

tract stimulant; cutting out fiber-rich foods can lead to chronic

constipation.

When Low-Fat Fails

Dr. Rolls's work helps to explain why so many people who reduced the

fat in their diets failed to lose weight and perhaps even gained. She

explained: " When the fat content of the diet is reduced but energy

density is held constant, people do not decrease their caloric

intake. But if energy density is reduced, no matter what the

macronutrient composition, ad libitum intake declines. "

That is, people eat less when there are fewer calories in a given

volume of food. If you cut back on fat and replace it with energy-

dense (that is, dry) carbohydrates like pretzels, crackers or sweets,

you may not be reducing your caloric intake. You may, in fact, be

increasing it.

Dr. Rolls's findings are good news for pasta lovers, who may be

avoiding this food in response to the current mania for low-carb

diets.

Start your meal with a salad or cup of soup, dish up a reasonable

portion of pasta (a serving is but two ounces of dry pasta), and top

it with lots of sautéed vegetables. With fruit and half a cup of

frozen yogurt for dessert, you have a filling, nutritious meal that

is not likely to add to your adipose depot and may even help you shed

some extra pounds.