Jenter og gutter se her for timing av næringsinntak for fettfri kroppsmasse!

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Timing is everything: if you think the fastest way to a lean body is to eat less and work out more, read on and learn about the surprising new research

August, 2004  by Martica Heaner

WHEN THE TORCH IS LIT IN Athens this summer, lots of athletes will be watching the clock--and not just because they don't want to miss their events. New research showing that when you eat is just as important as what you eat has resulted in several elite athletes changing their eating habits. By concentrating on timing their meals and snacks just right, many of them have now been able to report being leaner, less fatigued and more focused. "We've found that athletes who match their food intake to their energy expenditure at any given hour not only are less likely to 'bonk,' they are more mentally alert and have better muscle-to-fat composition than athletes who eat erratically," confirms Dan Benardot, PhD, RD, one of a group of nutritionists and exercise physiologists at Georgia State University (Atlanta) at the forefront of studying the effects of meal timing on athletic performance.

While the athletic diet has been analyzed to death, looking at the timing of eating is new--and it's changing the way competitors eat, as well as how active, recreational exercisers eat. Here's what you need to know to develop your own optimal eating schedule.

I LEARN THE NEW ENERGY EQUATION

Common wisdom has it that if the amount of calories you consume equals the amount of calories you burn, you'll stay in energy balance, and neither gain nor lose weight. That's been the assumption, anyway. But Benardot and his colleagues' research essentially throws that traditional energy equation out the window. The researchers found that when and how often their athletes took in calories throughout the day made a big difference in each person's day-end energy balance.

One study, for instance, showed that female gymnasts and runners who didn't eat or snack for three hours or longer had the highest body fat percentages--even if they weren't consuming more calories than they were burning. Furthermore, the longer the gap between eating times, the higher the body fat, especially if they exercised during those noneating periods. Keep in mind that these were competitive athletes training hours every day--they weren't overweight. But when compared to fellow runners and gymnasts, those who ate fewer and bigger meals retained higher levels of body fat.

Perhaps even more surprising, the same study showed that those who ate less than their energy needs--traditionally the recipe for weight loss-weren't losing weight. The runners, for example, ate an average of 200 to 400 fewer daily calories than they were burning, and some of these athletes reached points during the day when, because they were performing intense exercise without having eaten recently, they dipped into a caloric deficit of up to 1,100 calories for a few hours. But these exercisers were not losing weight, as you'd expect; in fact, they were among the "fattest" of the bunch. The reason, suspects Benardot, is that when deprived of food, even for just a few hours, the body desperately clings to any calorie it gets.

II THWART THE FAT-STORAGE INSTINCT

To elaborate on the calorie-clinging theory, Benardot explains that if you expend lots of extra energy when the body is underfed, the fuel the body needs in the form of liver and muscle glycogen (stored carbohydrate) is nowhere to be found. To cope, the body takes the irregular step of converting proteins in muscle tissue into blood glucose that it can use for energy. In other words, exercise on a long-empty stomach and you'll lose and weaken muscle.

And there's more. Since the body senses that food is in short supply, it shifts into starvation mode, which means that the next time you eat, there will be a larger-than-normal insulin response in an effort to capture the calories coming in. That, and the fact that the fat-storing enzyme, lipoprotein lipase, revs up higher than usual, results in a greater number of the newly ingested calories being tucked away as fat. "Now," the body thinks in its infinite yet out-of-date wisdom, "I'll be prepared for future times of famine."

One other factor that may determine why some people who go several hours without meals or snacks tend to have more body fat is that infrequent eating impairs appetite regulation, and that can lead to bingeing. Moreover, those who don't snack tend to play catch-up by eating oversize meals. "When you gorge after long periods without eating, the body is overloaded and becomes even more efficient at storing the extra calories as fat," explains John Ivy, PhD, a physiologist at the University of Texas and co-author of Nutrient Timing (Basic Health, 2004).

III DETERMINE WHAT YOU NEED, WHEN

Benardot's research demonstrates that it's key not to hit a calorie deficit or a calorie surplus greater than 300. Of course, short of living in a laboratory, there's no surefire way to know your exact energy-balance status at any given time. But you can avoid oversize deficits and surpluses by eating small- to moderate-size meals every three to four hours. And if you're going to work out in intense or long exercise sessions, eat more before and during to compensate. "If you ate a few hours earlier but are about to take a spin class followed by a weight-lifting session, you need enough fuel during that time to avoid diving into energy deficit," says Karen Dolins, EdD, RD, a nutrition professor at Columbia University in New York City and a nutritionist who follows these guidelines with her clients. "So burning around 700 calories doing a 90-minute workout means you need about 400 before and during so that you don't accrue a deficit of more than 300 calories."

For many women, this means paying particular attention to breakfast--a meal that's commonly skipped by morning exercisers, some of whom believe it's a way to get the body to dip into its fat stores. "You will burn a higher percentage of fat, but you won't burn more calories, which is what really affects weight," says Benardot.

Some athletes are also under the impression that hunger pangs before practice mean that the body will be able to divert all of its energy to the workout instead of to digestion. But while eating too much too close to intense training can slow down a practice, so can not eating enough. If your stomach is sensitive to more than just the smallest pre-workout snack, try to replenish your calories every 15 to 20 minutes with quick-absorbing carbs, like those found in sports drinks.

As you consider your food timing, keep in mind that one of the most crucial times to eat is right after an intense workout. Within the first 45 minutes or so postexercise--what physiologist Ivy calls the "metabolic window"--the enzymes that replenish glycogen in the muscles are at their highest. Plus, insulin, which rebuilds protein stores, is also at peak levels. So eating a carb-and-protein mix (peanut butter sandwich, yogurt with fruit, or nuts) right after training will increase your muscles' ability to rebuild themselves, replenish your glycogen stores and reduce the amount of fat that your body stores.

Missing this metabolic window can be bad news. "If you delay refueling, you'll slow glycogen replenishment by 50 percent and protein repair by 80 percent," says Ivy.

IV THE APPETITE CONTROL BONUS

Will you eat more if you eat more often? In a word, no. In fact, stabilizing your body with a constant fuel supply will likely help better regulate your appetite. "We found that giving athletes 750 calories' worth of snacks did not increase their overall food intake, because they automatically--and subconsciously--reduced the size of their meals," says Benardot.

Plus, numerous studies have shown that people who eat more often binge less because they aren't as hungry when mealtime comes around. Many athletes agree. "The best thing about eating around six meals and snacks a day is that you never become so famished that you eat enough to go into a 'food coma,'" says Jessi Stensland, a triathlete who's an alternate on the 2004 U.S. Olympic team. "When I eat something every three hours. I feel light and ready for anything."

By MARTICA HEANER, MA, MEd

COPYRIGHT 2004 Gale Group

[Benpressmannen]

Nutrition Performance
By Anssi H. Manninen, MHS
Metabolic Advantage: A Calorie is Not a Calorie
“Four stages of acceptance:
1) This is worthless nonsense;
2) This is an interesting, but perverse, point of view;
3) This is true, but quite unimportant;
4) I always said so.”
—J.B.S. Haldane, Journal of Genetics 58, p.464., 1963
Considerable attention has been given to the alarming rise in incidence of
overweight and obesity in the U.S. The latest National Health and Nutrition
Examination Survey (NHANES) shows that 64.5 percent of the U.S. population 20
years of age and older is now classified as overweight or obese!
The first law of thermodynamics describes one of the most important
principles related to obesity. The basic tenet states that energy cannot be created
or destroyed but, instead, transform from one form to another. That human beings
obeyed the first law of thermodynamics was demonstrated by Drs. Atwater and
Benedict in 1903 and has been continually reaffirmed since then.
In accord with the first law of thermodynamics, the energy equation dictates that
body mass remains constant when caloric intake is equal caloric expenditure. Any
chronic caloric imbalance on the energy output or input side of the equation
changes body mass.
Interestingly, published studies show that low-carbohydrate weight loss
diets provide a metabolic advantage, a greater weight loss per calorie consumed
compared to isocaloric high-carbohydrate diets.1 Unfortunately, these reports have
been largely ignored (“don´t confuse me with the facts”), presumably because of
apparent violation of thermodynamics (“a calorie is a calorie”). However, there is no
such violation of thermodynamic laws. Energy utilization of different diets depends
on the biochemical pathway taken; a metabolic analysis of the efficiency of
different pathways reveals large differences. Thus, there is no theoretical
contradiction in metabolic advantage and no theoretical barrier to accepting reports
describing this effect.1
Don’t Confuse Me with the Facts
According to a comprehensive literature review by Dr. Marjorie Freedman
and colleagues at the U.S. Department of Agriculture published in 2001, “No
scientific evidence exists to suggest that low-CHO [carbohydrate] ketogenic diets
have a metabolic advantage over more conventional diets for weight loss. Studies
consistently show that under conditions of negative energy balance, weight loss is
a function of caloric intake, not diet composition”.2
However, in a recent study by Dr. B. Brehm and colleagues, 53 healthy,
obese female volunteers were randomized for six months to either an ad libitum
very-low-carbohydrate diet (20-60 grams/day) or a caloric-restricted diet with 30
percent of the total calories as fat, 55 percent as carbohydrate and 15 percent as
protein.3 The women were examined at baseline, three months and six months.
Results showed that despite ingesting approximately the same number of calories,
women on the very-low-carbohydrate diets lost significantly more weight than did
those on the caloric-restricted diet (8.5 vs. 3.9 kilograms; ~18.7 pounds vs.~8.6
pounds).
In another study by Dr. F. Samaha and co-workers, 132 severely obese
men and women with either diabetes or metabolic syndrome were assigned to
either a low-carbohydrate or a caloric-restricted low-fat diet for six months.4
Seventy-nine subjects completed the study, which showed that those on the lowcarbohydrate
diet lost significantly more weight (5.8 vs. 1.9 kilograms; ~12.7 vs.
~4.2 pounds) and had greater improvements in triglycerides and improvements in
insulin sensitivity than those on the low-fat diet.
Finally, Dr. Penelope Greene and colleagues at the Harvard School of
Public Health found that people eating an extra 300 calories a day on a low-
carbohydrate diet diet lost a similar amount of weight during a 12-week study as
those on a low-fat diet.5 Over the course of the study, they consumed an extra
25,000 calories. That should have added up to about seven pounds. But it did not.
The study was unique because all the food was prepared at an upscale Italian
restaurant, so research knew exactly what they ate.
Not even Dr. Greene says this settles the case, but some found her findings
fascinating. “A lot of our assumptions about a calorie is a calorie are being
challenged,” said Dr. Marlene Scwartz of Yale. “As scientists, we need to be openminded.”
Others, though, found the data hard to swallow. “It doesn´t make sense,
does it?” said Dr. Barbara Rolls of Pennsylvania State University. “It violates the
laws of thermodynamics. No one has ever found any miraculous metabolic effects.”
Hmmm… who is Dr. Rolls?
Barbara J. Rolls, PhD, John Hopkins University School of Medicine (1992)
(owned by none other than Mayor Michael Bloomberg of New York who was
recently lambasted publicly for criticizing Dr. Atkins personally); professor of
nutrition, Penn State University; consultant for Knoll Pharmaceuticals and has
received research support from, among others, Knoll, P&G and ILSI. Co-authored
(with James O. Hill) a 1998 report for ILSI on carbohydrates and weight
management. Thus, it appears she is a carb industry shill.
What the Heck is Metabolic Advantage, Anyway?
Recently, Drs. Richard D. Feinman and Eugene J. Fine published state-ofthe-
art paper on metabolic advantage and weight loss diets in a new scientific
journal called Metabolic Syndrome and Related Disorders.1 In this review, they
tabulated some of the experimental demonstrations of metabolic advantage. They
showed that the apparent loss in energy in low-carbohydrate studies can be
accounted for by differences in pathways and metabolic cycles and that this will
appear as a thermogenic effect, as well as changes in body composition. Further,
they proposed a plausible mechanism for metabolic advantage on lowcarbohydrate
diets. Finally, they provided a brief thermodynamic analysis and
showed that, in fact, there is no barrier to accepting the published results.
Thermogenesis (thermic effect of feeding) refers to heat generated in
digestion and metabolism after feeding. Studies of macronutrient effects on
thermogenesis show a substantially greater effect of protein compared to
carbohydrate or fat. Thus, the energetically expensive protein turnover is a likely
source of metabolic advantage on low-carbohydrate diets. Interestingly, there may
also be a contribution due to the level of protein per se, independent of, or more
likely, synergistic with, carbohydrate content. A recent study by Dr. Carol Johnston
and co-workers found a 100 percent increase in thermogenesis with an 1,800
calorie low-fat diet with high protein compared to an isocaloric high-carbohydrate
diet.6
Bottom Line
According to Drs. Feinman and Fine, “The review presented here indicates
that the reported metabolic advantage of low-carbohydrate diets has a plausible
mechanism and is consistent with physical laws… Although the decline in body
mass on weight loss diets is frequently proportional to caloric intake, a diet that
offered the possibility of metabolic advantage would be of great practical value.”
There are always some concerns about high-protein diets. For individuals with
normal kidney and liver function, the risks are minimal and must be balanced
against the real and established risk of continued obesity. The ridiculous notion
that there is a single best diet for the whole population, as embodied, for example,
in the pseudoscientific USDA Food Pyramid, is under attack in the popular and
scientific press. Obviously, individual dieters must try different regimens to see
which is the most effective and fits their individual lifestyles.
Guidelines for Dieting Bodybuilders and other Power-Strength Athletes
• In my opinion, energy restriction is best achieved by a high-protein,
moderate-carbohydrate, low-fat diet.
• Protein intake should be about 1.5-2.5 grams per kilogram of body weight.
The upper level of protein is recommended if energy restriction is
substantial, as this may assist the maintenance of lean body mass and
promote satiety. Eat low-fat/high-protein meat (e.g., fish, lean meat, skinless
poultry) and low-fat/fat-free dairy products.
• Increase consumption of non-starchy vegetables and low glycemic load
fruits. Reduce intake of high-glycemic load carbohydrates with highcarbohydrate
densities such as starches (e.g,, potatoes, pasta, rice) and
grains. Consume moderate amounts of legumes.
• Have most of the total fat intake be from nuts and oils that are rich in
monounsaturated fats (e.g., olive oil).
• Set a realistic rate of weight loss (i.e., 0.5 to 1.0 kilograms, or about one to
two pounds, per week), including both short- and long-term goals.
• Keeping a food record for a defined period (e.g., a week) is a useful task
that allows you to appreciate exactly what you are eating.
• A moderate energy restriction of 500 to 1,000 kilocalories per day is
appropriate to producing a reasonable loss of body fat but still ensures
adequate nutrient intake.
• The meal plan for weight loss should not rely on skipping meals or enduring
long periods without food intake. Rather, food intake should be spread over
the day, particularly to allow for efficient refueling before and after training
sessions and to avoid hunger (which generally precipitates overeating).
• Use a broad-range, low-dose vitamin-mineral supplement if you will restrict
energy intake for prolonged periods.
• A significant part of weight loss and management may involve restructuring
the environment that promotes overeating. Simple changes that can modify
the eating environment: 1) prepare meals at home and carry bag lunches; 2)
learn to estimate or measure portion sizes in restaurants; 3) learn to
recognize fat content of menu items and dishes on buffet tables; and 4)
modify the route to work to avoid a favorite food shop.
• A myth that is circulating contends that in order to burn fat, you must
exercise at a lower percentage of your maximal oxygen uptake (VO2max).
This is certainly not the case. It is true that the percentage of energy
obtained from fat is greater at lower exercise intensities (e.g., 50 percent
VO2max) than at higher exercise intensities (e.g., 70 percent VO2max).
However, at the higher energy intensity, you will derive a lower percentage
of your energy output from fat, but the total energy expenditure will be
greater, and you will still burn about the same amount of fat calories as you
would exercising at the lower intensity, providing you are exercising for the
same amount of time. If you want to burn calories to lose body fat, your
objective should be to burn the greatest total calories possible within the
time frame you have to exercise.
• Exercise, particularly intense exercise, may be used to curb appetite on a
short-term basis at an appropriate time. If you exercise before a meal, your
food intake may be reduced considerably. Try it and see if it works for you. If
you have the facilities available, a good half-hour exercise may be an
effective substitute for a large lunch.
• There are two medications approved for the long-term treatment of obesity.
Sibutatramine is a norepinephrine and serotonin reuptake inhibitor that
inhibits food intake centrally; orlistat is an inhibitor of pancreatic lipase
functions. Although generally well tolerated, orlistat can give gastrointestinal
symptoms such as abdominal cramps, soft stools and fecal urgency. If these
symptoms were to occur during exercise, training disruptions could result.
Phenylpropanolamine is approved for the short-term treatment of obesity
(fewer than 12 weeks). Phenylpropanolamine is a central alpha-1 adrenergic
stimulator that has no addictive potential and gives weight loss equivalent to
prescription anorectic drugs during the first four weeks of treatment.
Phenylpropanolamine has a remarkable safety record.
8 Finally, a variety of drugs currently on the market for other conditions, but not approved by the FDA for obesity
treatment, have been evaluated for their ability to induce weight loss.
Metformin, cimetidine, diazoxide, bromocriptine, nicotine, bupropion and
topiramate have produced modest weight loss.9 However, additional studies
are needed to support these findings. Potential obesity drug candidates
include cholecystokinin, corticotropin-releasing hormone, glucagons-like
peptide 1, growth hormone and other growth factors, enterostatin,
neurotensin, vasopressin, anorectin, ciliary neurotrophic factor, and
bombesin, all of which potentially either inhibit food intake or reduce body
weight in humans or animals.9
References
1. Feinman RD, Fine EJ (2003) Thermodynamics and metabolic advantage of weight loss
diets. Metabolic Syndrome and Related Disorders, 1:209-219.
2. Freedman M, MR, King J, Kennedy E (2001) Popular Diets: A Scientific Review. Obes Res,
9:1S-34S.
3. Brehm BJ, Seeley RJ et al. (2003) A randomized trial comparing a very low carbohydrate
diet and a calorie-restricted low fat diet on body weight and cardiovascular risk factors in
healthy women. J Clin Endocrinol Metab, 88:1617-1623.
4. Samaha FF, Iqbal N et al. (2003) A low-carbohydrate diet as compared to with a low-fat diet
in severe obesity. N Engl J Med, 348:2074-2081.
5. Greene P, Willett W et al. (2003) Pilot 12-week feeding weight loss comparison: low-fat vs.
low-carbohydrate (ketogenic) diets [abstract]. Obes Res, 11:A23.
6. Johnston CS, Day CS et al. (2002) Postprandial thermogenesis is increased 100% on a
high-protein, low-fat diet versus a high-carbohydrate, low-fat diet in healthy, young women.
J Am Coll Nutr, 21:55-61.
7. Bell SJ, Sears B (2003) A proposal for a new national diet: A low-glycemic load diet with a
unique macronutrient composition. Metabolic Syndrome and Related Disorders, 1:199-208.
8. Greenway F (2003) Use of pharmacological aids in weight management. In: Weight
Management: State of the Science and Opportunities for Military Programs. Committee on
Military Nutrition Research, Food and Nutrition Board, Institute of Medicine. Washington,
D.C.: National Academies Press, p. 213-217.
9. Committee on Military Nutrition Research (2003) Weight-loss and maintenance strategies.
In: Weight Management: State of the Science and Opportunities for Military Programs.
Committee on Military Nutrition Research, Food and Nutrition Board, Institute of Medicine.
Washington, D.C.: National Academies Press, p. 79-111.