The South Beach Diet is relatively simple in principle. It replaces "bad
carbs" and "bad fats" with "good carbs" and "good
fats."
According to Agatston, hunger cycles are triggered not by carbohydrates in
general, but by carbohydrate-rich foods that the body digests quickly, creating
a spike in blood sugar. Such foods include the heavily refined sugars and grains
that make up a large part of the typical Western diet. The South Beach Diet
eliminates these carbohydrate sources in favor of relatively unprocessed foods
such as vegetables, beans, and whole grains.
"Good fats" vs "Bad fats"
Given that South Beach Diet was designed by a cardiologist, it should be no
surprise that it eliminates trans-fats and discourages saturated fats. Although
foods rich in these "bad fats" do not contribute to the hunger cycle,
they do contribute to LDL cholesterol and heart disease. The South Beach Diet
replaces them with foods rich in unsaturated fats and omega-3 fatty acid which
contribute to HDL cholesterol and provide other health benefits. Specifically,
the diet excludes the fatty portions of red meat and poultry, replacing them
with lean meats, nuts, and oily fish.
Phases
Agatston divides the South Beach Diet into three phases, each progressively
becoming more liberal. "Phase 1" lasts for the first two weeks of the
diet. It eliminates all sugars, processed carbohydrates, fruits, and some
higher-glycemic vegetables as well. Its purpose is to eliminate the hunger cycle
and is expected to result in significant weight loss. "Phase 2"
continues as long as the dieter wishes to lose weight. It re-introduces most
fruits and vegetables and some whole grains as well. "Phase 3" is the
maintenance phase and lasts for life. There is no specific list of permitted and
prohibited foods. Instead, the dieter is expected to understand the basic
principles of the diet and live by them.
Diabetic Diet
For more information about the diabetic diet visit: AMERICAN DIABETIC
ASSOCIATION
In the 1950s, the American Diabetes Association, in conjunction
with the U.S. Public Health Service, brought forth the "exchange
scheme". This was a scheme that allowed people to swap foods of similar
nutritional value (e.g. carbohydrate) for another, so, for example, if wishing
to have more than normal carbohydrates for pudding, one could cut back on
potatoes in one's first course. The exchange scheme was revised in 1976, 1986
and 1995 (Chalmers & Peterson, 1999, p85). However, not all diabetes
dietitians today recommend the exchange scheme. Instead, they are likely to
recommend a typical healthy diet: one high in fiber, with a variety of fruit and
vegetables, and low in both sugar and fat, especially saturated fat. A diet that
is high in plant fibre was recommended by James Anderson (Anderson & Ward,
1979; cited in Murray & Pizzorno, 1990). This may be understood as
continuation of the work of Burkitt and Trowell on dietary fibre, which in turn,
may be understood as a continuation of the work of Price (Murray & Pizzorno,
1990). Murray and Pizzorno discusses the high-carbohydrate, high-plant fibre
diet (HCF diet) in connection with diabetes.
Atkins
The Atkins Diet is a departure from the previously prevailing metabolic
theories. Atkins claimed there are two important unrecognized factors in Western
eating habits which lead to obesity. First, the main cause of obesity is eating
refined carbohydrates, particularly sugar, flour, and high-fructose corn syrups.
Secondly, that saturated fat is overrated as a nutritional problem, being not as
important in developing vascular disease, and that trans fats from sources such
as hydrogenated oils are much more important in developing vascular disease.
Accordingly, Dr. Atkins rejected conventional nutritional advice (eg, that
embodied in the food pyramid), instead claiming that the tremendous increase in
refined carbohydrates has been responsible for the rise in metabolic disorders
of the 20th century, and that the focus on the detrimental effects of dietary
fat has actually contributed to the obesity problem by neglecting the increased
proportion of carbohydrates in the diet. While Atkins puts his emphasis on diet,
nutritional supplements and exercise are also considered important elements.
The Atkins Diet involves restriction of carbohydrates to more frequently
switch the body's metabolism from burning glucose as fuel to burning stored body
fat. This process (called ketosis) begins when insulin levels are low; in
normal humans, insulin is lowest when blood glucose levels are low (mostly
before eating), and blood glucose levels are most fundamentally increased by
ingestion of some kinds of carbohydrate (eg, glucose, starch (ie, long glucose
chains)). Other kinds of carbohydrates don't participate in the insulin
mechanism controlling metabolism. Ketosis involves lipolysis in which
some of the lipid stores in fat cells are transferred to the blood.
In his book Dr Atkins' New Diet Revolution, Dr. Atkins claimed that
the low-carbohydrate diet produces a metabolic advantage in which the body burns
more calories, overall, than on normal diets, and also expels some unused
calories. He cited one study where he estimated this advantage to be 950
calories (4.0 MJ) a day. However, a review study published in the Lancet
concluded that there was no such metabolic advantage and
dieters were simply eating fewer calories due to boredom. Professor Astrup
stating that "The monotony and simplicity of the diet could inhibit
appetite and food intake", or possibly protein inducing a satiating effect.
The Atkins Diet restricts "net carbs" (carbohydrates that have an
effect on blood sugar). One effect is a tendency to decrease the onset of
hunger, perhaps due to longer duration of digestion (fats and proteins take
longer to digest than carbohydrates). Dr. Atkins says in Dr. Atkins' New Diet
Revolution (2002) that hunger is the number one reason why low-fat diets fail.
Though studies show the efficacy of the Atkins approach after one year is the
same as some low-fat diets, Dr. Atkins claimed that it was easier to stay on the
Atkins diet because dieters did not feel as hungry or "deprived".
Net carbohydrates can be calculated from a food source by subtracting fiber
and sugar alcohols (which are shown to have a negligible effect on blood sugar
levels) from total carbohydrates. Sugar alcohols need to be treated with
caution, because while they may be slower to convert to glucose, they can be a
significant source of glycemic load and can stall weight loss. Fructose (eg, as
found in many industrial sweeteners) also contributes to caloric intake, though
outside of the glucose-insulin metabolic control loop.
Preferred foods in all categories are whole, unprocessed foods with a low
glycemic load. Atkins Nutritionals, the company formed to market foods which
work with the Atkins Diet, recommends that no more than 20% of calories eaten
while on the diet come from saturated fat.
According to the book Atkins Diabetes Revolution, for people whose
blood sugar is abnormally high or who have Type 2 diabetes mellitus, this diet
decreases or eliminates the need for drugs to treat these conditions. The Atkins
Blood Sugar Control Program (ABSCP) is an individualized approach to weight
control and permanent management of the risk factors for diabetes and
cardiovascular disease. Nevertheless, the causes of Type 2 diabetes remain
obscure, and the Atkins Diet is not accepted in conventional therapy for
diabetes.