Excerpts
from Harvard Health Letter
Low-carb, high-protein
diets often grab attention. The Paleo, South Beach, and Atkins all fall into
this category. They are also called ketogenic or "keto" diets.
But a true ketogenic diet unlike other low-carb diets (which focus on protein)
centers on fat, which supplies as much as 90% of daily calories.
The keto diet
is primarily used to help reduce the frequency of epileptic seizures in
children. For weight loss only short-term results are available. We don't know
if it works in the long term, nor whether it's safe.
The keto diet
aims to force your body into using a different type of fuel. Instead of relying
on sugar (glucose) that comes from carbohydrates (such as grains, legumes,
vegetables, and fruits), the diet relies on ketone bodies (fuel that the liver
produces from stored fat).
Burning fat
seems like an ideal way to lose pounds. But getting the liver to make ketone
bodies is tricky. It requires that you deprive yourself of carbohydrates, fewer
than 20 to 50 grams of carbs per day (medium-sized banana has 27 grams of
carbs). It typically takes a few days to reach a state of ketosis and eating
too much protein can interfere with ketosis.
Because the
keto diet has such a high fat requirement, followers must eat fat at each meal.
In a daily 2,000-calorie diet, that might look like 165 grams of fat, 40 grams
of carbs, and 75 grams of protein. Some healthy unsaturated fats are
allowed on the keto diet — like nuts (almonds, walnuts), seeds, avocados, tofu,
and olive oil. But saturated fats from oils (palm, coconut), lard, butter, and
cocoa butter are encouraged in high amounts. Protein is part of the keto diet,
but it doesn't typically discriminate between lean protein foods and protein
sources high in saturated fat such as beef, pork, and bacon.
All fruits are
rich in carbs, but you can have certain fruits (usually berries) in small
portions. Vegetables (also rich in carbs) are restricted to leafy greens (such
as kale, Swiss chard, spinach), cauliflower, broccoli, Brussels sprouts,
asparagus, bell peppers, onions, garlic, mushrooms, cucumber, celery, and
summer squashes. A cup of chopped broccoli has about six carbs.
Ketogenic
diet has numerous risks.
· It’s high in saturated fat.
One is supposed to keep saturated fats to no more than 7% of your daily
calories because of the link to heart disease. Keto diet is associated with an
increase in "bad" LDL cholesterol, which is also linked to heart disease.
· If you’re not eating a wide
variety of vegetables, fruits, and grains, you may be at risk for deficiencies
in micronutrients, including selenium, magnesium, phosphorus, and vitamins B
and C.
· With so much fat to
metabolize, the diet could make any existing liver conditions worse.
· The kidneys help metabolize
protein, and the keto diet may overload them. (The current recommended intake
for protein averages 46 grams per day for women, and 56 grams for men).
· The keto diet is low in
fibrous foods like grains and legumes. It can lead to constipation.
· The brain needs sugar from
healthy carbohydrates to function. Low-carb diets may cause confusion and
irritability.
The popular
low-carb diets (such as Atkins or Paleo) modify a true keto diet. But they come
with the same risks if you overdo it on fats and proteins and lay off the
carbs.
(Source: Harvard Health Letter (Dept. of
Nutrition at Harvard-affiliated Brigham and Women's Hospital)
Dr KK Aggarwal
Padma Shri
Awardee
President Elect Confederation of Medical Associations in Asia and Oceania (CMAAO)
Group
Editor-in-Chief IJCP Publications
President
Heart Care Foundation of India
Immediate Past National President IMA
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