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| Reyna F |
This is
Part 2 of a two part blog post on metabolism.
Part 1 explained RMR/BMR and how to determine these
factors (click
here).
Part 2 explains what will and
will not impact metabolism.
Part 2 is written in a myth-busting format since I get
so many interesting questions regarding how to increase metabolism.
See how many True/False questions you get
right!
Your body burns more calories
digesting ice cold beverages and foods (T/F)
True. But the small difference in calories
probably won't make a significant dent in your diet. Different studies have
suggested that five or six ice-cold glasses of water could help you burn about
10 extra calories a day equaling about 1 pound of weight loss each year.
Drinking the right amount of water can
help you burn more calories (T/F)
True.
There are 2 theories:
1. All of your body's chemical reactions,
including your metabolism, depend on water. If you are dehydrated, you may be
burning up to 2% fewer calories, according to researchers at the University of Utah who monitored the metabolic rates
of 10 adults as they drank varying amounts of water per day. In the study,
those who drank either eight or twelve 8-oz glasses of water a day had
higher metabolic rates than those who had four.
2. In 2003, an article was published in
the Journal of Clinical Endocrinology and Metabolism. It spoke of a
study involving seven healthy men and seven healthy women. All participants
were of normal weight. Each participant consumed 500 ml of water per day (a half-liter or about a pint). When their
metabolic rates were measured, the researchers found that all metabolic rates
were increased by roughly 30 percent. This spike in the metabolism, according to the study, occurred quickly after water
consumption: the metabolism was at its greatest spike within a half an hour and
was maintained for more than an hour. In that time they burned an extra 25
calories.
What is the reason for this? Researchers theorized that most of the
effect comes from warming the water in the stomach. In the male participants, the calories came mostly from stored fat, in the women it came from stored
carbohydrates. The water enters the body cold and must be warmed up in the
stomach. This "warming up" causes the body's metabolism to increase
briefly. This study further
substantiates the idea that ice water, in particular, can help burn calories.
Just as the researchers stated above, the ice water in your system must be
warmed up by your body. It goes in cold, but when it exits it's no longer
freezing. The conversion from ice water to warm water burns calories.
Dieting drops your resting metabolic
rate, making it harder to keep weight off (T/F)
True. For every pound you lose, your resting metabolism drops by about 2 to 10 calories a day. Lose 10 pounds, and you now have to eat 20 to 100 fewer calories to maintain your trimmer physique, not factoring in exercise. However, you can prevent your metabolic rate from slipping while you get slim. One way is to lose fat but maintain muscle. You can do this by reducing calories and increasing aerobic and resistance exercise.
Hot foods will fire up metabolism
(T/F)
True. While capsaicin is often linked to an increased
metabolic rate, specific information varies by study.
ü
In 2008, a study published in
the Journal of Biological Chemistry indicated that "the consumption of
[capsaicin] is linked with increased metabolic rate and core body
temperature." The study
found the active chemical in peppers can directly induce thermogenesis, the process by which cells convert energy into heat.
ü Another
study reports that about 1 tbsp. or 30 milligrams of capsaicin, or one
tablespoon of chopped red or green chili pepper, has been shown to temporarily
boost metabolism by 23 percent.
ü Stanford
University claims that there could be as much as a "50 percent increase in
metabolism for three hours after eating capsaicin."
ü Other
reports indicate that an increase may be as negligible as less than 10 percent.
Eating more protein will rev up your metabolism (T/F)
True. Evidence exists that
protein exerts an increased thermic effect when compared to fat and
carbohydrate. Evidence is also convincing that higher protein diets
increase satiety when compared to lower protein diets. In general,
the typical thermic effect of protein is 20% – 35% of energy consumed,
and for carbohydrate this number usually falls between 5% –15%.
The thermic effect of fat is a subject of debate. Some have found
that fat has a lower thermic effect compared to carbohydrate, while others have
found no difference between the two. A main reason for the difference in the
thermic effects of food may be due to the fact that the body has no
storage capacity for protein and thus it needs to be metabolically
processed immediately. The synthesis of protein, the high ATP cost
of peptide bond synthesis as well as the high cost of urea
production and gluconeogenesis are often cited reasons for the
higher thermic effect of protein.

Eating a grapefruit before every meal
speeds metabolism (T/F)
False. Grapefruit won't work
miracles for your metabolism, but it can help you lose weight. Half a
grapefruit before meals helped individuals lose about 4 pounds in 12 weeks,
according to a study published in the Journal of Medicinal Food. The reason: its fiber and water fill you up on fewer calories, so you eat less at your next
meal.
Celery is a "negative calorie
food" because digesting it uses up more calories than it provides
(T/F)
False. The thermal effect of food (TEF) causes the body to burn calories
as it processes food. But this process accounts for anywhere from 0 to 30% of
the calories consumed. A medium size rib of celery has about 6 calories; its
TEF is approximately 1/2 a calorie.
If you have limited time, exercise at
a higher intensity for a metabolic after-burn. (T/F)
True. The exercise
after-burn, or the calories expended (above resting values) after an exercise
bout, is referred to as ‘excess post-exercise oxygen consumption’ or EPOC. This
represents the oxygen consumption above resting level that the body is
utilizing to return itself to its pre-exercise state.
The physiological
mechanisms responsible for this increased metabolism include the replenishment
of oxygen stores, phosphagen (ATP-PC) resynthesis, lactate removal, and the
increased ventilation, blood circulation and body temperature above
pre-exercise levels. Studies have found that the magnitude and duration of EPOC
is dependent on the intensity and duration of exercise. It generally takes
anywhere from 15 minutes to 48 hours for the body to fully recover to a resting
state. Other factors influencing EPOC include training status and gender.
Lifting weights boosts your metabolism
more than a cardio workout (T/F)
False. Leading exercise physiologists
conducted a comprehensive review of the research on exercise and weight loss
for the American College of Sports. While resistance
training was recommended for its beneficial role in potentially improving
muscle, strength and power, they found no evidence that it enhanced weight
loss, especially when combined with dieting.
A common claim is that every extra pound of muscle burns
from 30 to 50 calories per day. Some sources cite that one pound of muscle can
burn an extra 100 calories per day. In
reality, one pound of muscle burns about 7 to 15 calories a day.
A
high-intensity workout that combines weight training and cardio without any
breaks will raise your heart rate, burn the most calories and provide the longest
sustained metabolic boost--though it won't have a permanent effect on your RMR.
The increase in metabolism is due to the increased excess post-exercise oxygen consumption (EPOC) which some
people call the “after-burn”. EPOC is the
total oxygen consumed after exercise in excess of a pre-exercise baseline
level. The greater the EPOC, the longer you will burn calories. Incorporate high intensity interval training
(HIIT) and sprints for the increased “afterburn.”
PMS cravings
are related to the boost in metabolism before your period (T/F)
Studies do not agree: One theory states that our resting metabolic
rate may increase during the luteal phase of the menstrual cycle (the day after
ovulation to the first day of your period). The metabolic boost can equal as
much as 300 calories a day which is why our appetite increases during this
phase.
But another study indicates
metabolic rate and calorie expenditure do not increase during that time of the
month. What does happen is a change in hormones that cause an increase in
appetite to prepare the woman's body for pregnancy and to increase weight.
Green Tea boosts metabolism (T/F)
Possibly. Green tea is one of the most common herbal
supplements that is being added to thermogenic products because it has been
suggested to affect weight loss and is now the fourth most commonly used
dietary supplement in the U.S. Green tea contains high amounts of caffeine and
catechin polyphenols. The primary catechin that is associated with the
potential effects on weight loss through diet induced thermogenesis is the
catechin epigallocatechin gallate, also known as EGCG.
- Dulloo et al reported that
green tea supplementation in combination with caffeine (e.g., 50 mg
caffeine and 90 mg epigallocatechin gallate taken 3-times per day)
significantly increased 24-hour energy expenditure and fat utilization in
humans to a much greater extent than when an equivalent amount of caffeine
was evaluated suggesting a synergistic effect.
- Research by Di Pierro and
colleagues reported that the addition of a green tea extract to a
hypocaloric diet resulted in a significant increase in weight loss (14 kg
vs. 5 kg) versus a hypocaloric diet alone over a 90 day clinical trial.
- Maki and coworkers also
demonstrated that green tea catechin consumption enhanced the
exercise-induced changes in abdominal fat.
Green tea has been theorized to increase energy expenditure
by stimulating brown adipose tissue thermogenesis. Note there are also human and animal studies that have not supported these findings and have reported that supplementation of
these extracts does not affect weight loss.
What can you do to increase your metabolism?
- Exercise
more and/or add interval training and sprints into your weekly
workouts.
- Add
chili pepper and turmeric to food, and drink green tea.
- Include
weight training to maintain or build muscle mass, but include cardio for
weight loss and wellness.
- Avoid
products that are “metabolism boosters” since they are not regulated and
there are possible risks associated with these products. And once you stop
using them, you end up gaining the weight back.
References:
- American
Journal of Clinical Nutrition
- Journal
of Applied Physiology
- Journal of Biological
Chemistry
- Journal of the American College of Nutrition
- Journal
of the Academy for Nutrition and Dietetics
- Journal of the International
Society of Sports Nutrition
For more information, contact Reyna Franco
(
Reyna@reynafranco.com). She is a registered dietitian, certified personal
trainer, certified specialist in sports dietetics and NY Flyers member. Her office is located on the upper west side
and she counsels individuals and groups on sports and medical nutrition. Her new and improved website is
www.reynafranco.com.
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