NOTE: As a Registered Dietitian, I work with individuals to find a healthy balance between food, exercise, emotions, and life. I do not condone "diets," but often get asked about them. This post is not intended to encourage a particular eating pattern, but simply to inform. Please share your thoughts/questions in the comments section.
Paleo Diet
The Paleolithic diet
(ie, Paleo diet) emphasizes eating foods that those who lived during the
Paleolithic times, some 10,000 years ago, consumed. Humans
previously consumed only wild and unprocessed foods; therefore, their diet was high
in lean proteins, monounsaturated and polyunsaturated fats, fiber, vitamins,
minerals, antioxidants, and other phytochemicals. Some have suggested that this type of diet falls
more in line with human evolution than a cereal-based diet, which may explain the
lower incidence of chronic diseases such as type 2 diabetes, obesity,
and cardiovascular disease among hunter-gatherers.
Walter L. Voegtlin first
made the Paleo diet popular in the 1970s; since then, numerous authors and
researchers have revised and recreated it. Its focal foods are meat, fish,
vegetables (excluding potatoes and sweet potatoes), fruits, roots, and nuts
(excluding peanuts and cashews). It disallows grains, legumes, dairy products,
salt, flours, refined sugars, and processed oils, all of which became available
only after the development of agriculture. The Paleo diet is approximately 19%
to 35% protein, 22% to 40% carbohydrate, and 28% to 47% fat.
CrossFit, a core
strength and conditioning program that has been gaining in popularity,
encourages participants to follow the Paleo diet.
Pros: Some scientific studies
have revealed health benefits associated with the Paleo diet. Frassetto et al
found that even
short-term consumption of a Paleolithic-type
diet improved blood pressure and glucose tolerance, decreased insulin secretion, increased
insulin sensitivity, and improved lipid profiles without weight loss in healthy
sedentary humans.
The diet focuses on
eating animal proteins and foods that come from the Earth rather than processed
foods, supports “clean” eating and consuming whole foods, and is very satiating
due to its high fat and protein content. In addition, much of the fat consumed on
a Paleo-type diet is heart-healthy monounsaturated and polyunsaturated—especially
omega-3—fat.
Cons: The diet:
- is restrictive,
disallowing many foods, including pasta, bread, potatoes, and desserts;
- some may have an
initial “withdrawal” period due to eliminating coffee, sugar, alcohol, and
refined carbohydrates;
- may not promote
adequate calcium and carbohydrate intake; and
- is high in fat.
Bottom Line: The Paleo diet steers
followers away from processed foods and encourages clean eating, but it may be
too low in carbohydrate and calcium and too unrealistic/drastic for many people.
Additionally, in Paleolithic times, people were much more active than most are
today, which may have contributed to the observed reduced incidence of disease.
Raw Food Diet
Followers of the raw
food diet consume primarily uncooked, unprocessed plant foods. The main food
components of the diet are generally fruits, nuts, seeds, sprouted grains, and
beans. There are several variations of the raw food diet and there is no general
definition.
Proponents claim that if
followed correctly, the diet leads to a leaner body, clearer skin, and
increased energy. These claims are based on the theory that in their natural
state, plant foods are more wholesome for the body. Raw food proponents believe
that heating any food above 116˚F destroys important enzymes that aid
digestion and absorption of essential nourishment.
Pros: People following this
diet generally eat a great amount of fruits and vegetables, which are rich in
nutrients and fiber. Research has shown that people consuming a plant-based
diet usually have lower levels of cholesterol and triglycerides. Additionally,
it is true that overcooking foods can
have negative effects, such as reducting nutrient content or producing
hazardous byproducts (such as acrylamide, which is produced when starches are
cooked at very high heats for too long).
Cons:
- Because a raw food
diet lacks variety and animal proteins, it may promote vitamin B12 deficiency,
which can lead to anemia and neurological problems, and lower bone mass.
- A study published in
the Journal of Nutrition found that while this diet may lower total cholesterol
and triglycerides, it may also lower high-density lipoprotein cholesterol and
increase homocysteine concentrations due to vitamin B12 deficiency. Elevated
homocysteine is considered an independent risk factor for cardiovascular
disease.
- Overall, this is not
an easy diet to follow. It requires much preparation and organization and can limit
one’s ability to enjoy meals socially.
Bottom Line: While a diet rich in
fruits and vegetables is certainly beneficial to one’s health, raw foodists
purport some extreme views about cooking food that lack scientific merit. Eating raw fruits and vegetables is great, but eating raw
meat and fish can expose one to excess food safety risk. Plus, this diet
greatly limits ones ability to eat socially.
Baby Food Diet
This is one of
Hollywood’s latest diet crazes, with some well-known celebrities reportedly
following it. The diet involves eating jars of baby food to limit portions and
restrict calories. Followers either eat baby food as a snack to curb hunger or
substitute other foods with one or two jars of baby food—an average jar of baby
food is 15 to 110 kcal per serving—at lunch or dinner.
Pros: Baby foods are generally
rich in nutrients, free of additives, and portion-controlled. Organic varieties
are also available.
Cons:
- Small portions and
restrictive dieting can lead to binges.
- Baby foods taste
bland.
- Calorie intake may be
insufficient for the day, depending on the number of meals substituted for baby
food.
Bottom Line: Although baby food is a
nutrient-rich food option, limiting oneself to a jar or two of baby food for a
meal is a very restrictive practice for an adult. Caloric restriction is more
likely to induce binge-eating behaviors.
Apple Cider Vinegar Diet
In the 1950s, Dr. D.C.
Jarvis wrote Folk Medicine, which set the stage for apple cider vinegar as a
weight-loss agent.1 Jarvis claimed that regular consumption of the tonic would
cause the body to burn fat rather than store it. Other proponents have claimed
that the pectin in the vinegar binds and removes cholesterol from the body.
Supporters say that
consuming 1 to 3 tsp of apple cider vinegar 15 minutes before each meal will
aid weight loss. The apple cider vinegar diet does not prescribe a menu or
meal plan but recommends eating in moderation and skipping snacks. Proponents
suggest that over time, the vinegar will decrease hunger and cravings.
Pros: Apple cider vinegar is
inexpensive. Additionally, a small study published in Diabetes Care in 2004
found that vinegar significantly improved postprandial insulin sensitivity in
insulin-resistant subjects and possessed physiological effects similar to
acarbose or metformin, diabetes drugs that help control blood glucose. However,
further investigations into the efficacy of vinegar as an antidiabetic therapy
are warranted.
Cons: Currently there is no
solid evidence to support the use of apple cider vinegar for weight loss or
other medical purposes. According to WebMD.com, consuming 8 oz of apple cider
vinegar per day may lead to long-term problems such as low potassium and
osteoporosis. And although at
least one trial showed possible benefit to those with diabetes, WebMD.com
suggests that long-term use or high doses of apple cider vinegar might increase
potassium loss in people using insulin. In addition, apple cider vinegar:
- may cause stomach and
throat irritation due to its acidity;
- may cause bone loss
when used long-term;
- may interact with
other medications; and
- has a pungent taste.
Bottom Line: Some research shows that
supplementing the diet with apple cider vinegar may have some health benefits,
such as improving blood glucose control. But, since there are several potentially serious
risks associated with its consumption, consumers (especially those with
conditions such as osteoporosis or who take certain medications) should
exercise caution.
Grapefruit Diet
This diet has existed
since the 1930s. According to grapefruit-diet-plan.org, eating lots of
“fat-burning” grapefruit will kick-start metabolism. The plan lasts for 12
days, and according to the Web site, if people practice it correctly they can
lose up to 10 lbs.
There are several
variations to the grapefruit diet plan, but the principle behind each is the
same: Eat one half of a grapefruit before every meal to trigger fat-burning
capabilities. The Web site proclaims that there is no starvation with this
diet, yet it does state that followers should limit calories to less than 800
per day.
Pros: Grapefruit is a good
source of beta-carotene, fiber, and vitamin C. The white pith contains pectin
and bioflavonoids.
Cons:
- No scientific studies support
the claim that grapefruit contains “fat-burning enzymes.”
- The diet does not
supply adequate calories.
- It is a short-term,
temporary approach to weight loss.
Bottom Line: The grapefruit diet will
encourage people to eat more fruit throughout the day. However, the diet is too
low in calories. It is likely the calorie restriction rather than the action of
the grapefruit that will lead to weight loss.
Conclusion: There are many fad diets
out there, and their popularity knows no bounds. Fad dieting is often cyclical, causing weight fluctuation,
slowed metabolism, and a negative relationship with food. In my practice, I encourage clients to eliminate food restrictions and embrace all types of foods. This can very difficult for a lifelong dieter to do, but worthwhile. Dieting is temporary, but the need to eat
will never end. As a dietitian, one of my goals is to help people
understand their unique dietary needs and work toward creating a positive
relationship with food—and the scale.
References:
- Every Diet. Diet Plans encyclopedia. Available at: Everydiet.org. Accessed on May 13, 2010.
- Diets in Review.
Available at: www.dietsinreview.com. Accessed on May 13, 2010.
- Johnston
et al. Vinegar Improves
Insulin Sensitivity to a High-Carbohydrate Meal in Subjects With Insulin
Resistance or Type 2 Diabetes. Diabetes
Care. January 2004 vol. 27 no. 1 pp. 281-282.
- WebMD: Better
information. Better health. Available at:
www.webmd.com/vitamins-supplements/ingredientmono-816&activeIngredientName=APPLE+CIDER+VINEGAR.
Accessed on: May 13, 2010.
- Grapefruit Diet Plan
for Beginner. Available at: www.grapefruit-diet-plan.org.
Accessed on May 13, 2010.
- Frassetto, et al.
Metabolic and physiologic improvements from consuming a Paleolithic,
hunter-gatherer type diet: Health benefits of a Paleo diet. European Journal of
Clinical Nutrition. 63, 947-955, August 2009.
- O’Keefe, James H. & Cordain, Loren.
Cardiovascular Disease Resulting From a Diet
and Lifestyle at Odds With Our Paleolithic Genome:
How to Become a 21st-Century Hunter-Gatherer. Mayo Clin Proc. 2004;79:101-108.
- CrossFit. Available at:
http://www.crossfit.com/cf-info/start-diet.html. Accessed on May 13, 2010.
- Koebnick, et al.
Long-term consumption of a raw food diet is associated with favorable serum LDL
cholesterol and triglycerides but also with elevated plasma homocysteine and
low serum HDL cholesterol in humans. J. Nutr. 135: 2371-2378, Oct. 2005.
- Tribole & Resch.
Intuitive Eating: A Revolutionary Program that Works. St. Martin’s Griffin,
2003.
- Master Cleanse. What is the Master Cleanse? Available
at: http://themastercleanse.org/. Accessed on May 13, 2010.