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Should Low carb diets be High in Fat and not High in Protein?
by Andrea Simpson
So, where do we start. Our body needs carbs for energy and if we reduce the amount of carbs we need to replace it with energy, provided by either protein or fats.
Energy from protein While the body can use protein as an energy source in an emergency, it is not healthy to use this method in the long term. All carbs are made up of three elements: carbon, hydrogen and oxygen. All fats are made of the same three elements. Proteins, however, also contain nitrogen and other elements. When proteins are used to provide energy, these must be got rid of in some way. This is not only wasteful, it can also put a strain on the body, and in particular the liver and kidneys.
Increased levels of nitrogen leads, in a short space of time, to hyperammonaemia, which is a build up of ammonia in the bloodstream. This is toxic to the brain. Many cultures survive on a purely animal product diet, but only if it is high in fat. A lean meat diet, on the other hand cannot be tolerated; it leads to nausea in as little as three days, symptoms of starvation and ketosis in a week to ten days, severe debilitation in twelve days and possibly death in just a few weeks. A high-fat diet, however, is completely healthy for a lifetime.
Energy from Fats When most people think of eating a low-carb diet, they tend to think of it as being a protein-based one. This is false. All traditional carnivorous diets, whether eaten by animals or humans, are more fat than protein with a ratio of about eighty percent of calories from fat and twenty percent of calories from protein. Similarly, the main fuel produced by a modern low-carb diet should also be fatty acids derived from dietary fat and body fat.
Fats also produce ketone bodies. Ketones were first discovered in the urine of diabetic patients in the mid-19th century.Reduction of carbohydrate intake stimulates the synthesis of ketones from body fat.This is one reason why reducing carbs is important.
Ketone formation and a shift to using more fatty acids also reduces the bodys overall need for glucose. Even during high-energy demand from exercise, a low-carb diet has what are called glucoprotective effects. What this all means is that ketosis arising from a low-carb diet is capable of accommodating a wide range of metabolic demands to sustain body functions and health while not using, and thus sparing, protein from lean muscle tissue. Ketones are also the preferred energy source for highly active tissues such as heart and muscle.
All this means that more glucose is available to the brain and other essential glucose-dependent tissues.
Time for a balanced meal Studies into low carb diets suggest that we all have a level of dietary carbohydrate intake where the changeover from glucose-burning to fat and ketone burning takes place. This can vary between approx 65 and 180 grams of carbs/day. If your carb intake is below this threshold, then your body fat will be broken down to generate ketones to supply your brain and other cells that would normally use glucose. In the early trials for the treatment of obesity, carb levels were very much reduced to supply only about ten percent of calories. This works out at around fifty or sixty grams of carb for a 2,000 calorie daily intake.
For diabetics, the level may need to be lower to counteract insulin resistance. Typical levels of carb intake for a type-2 diabetic are around fifty grams per day; the level should be lower still at about thirty grams a day for a type-1 diabetic.
A typical balanced meal based on the above information consists of one part carb to two parts protein to between three and four parts fat, by weight. I see no reason to disagree with this. What it means in practice is that on a 2,000 calorie per day diet, we should get:
- Ten to fifteen percent of calories from carbs - Twenty to thirty percent of calories from protein and - Sixty to seventy percent of calories from fats.
Or another way to look at it is to consume (daily) 50 to 75grams of carb and the rest from meat, fish, eggs, cheese, and their natural fats.
This article is based on research by Professor John Yudkin and provides additional food for thought,pardon the pun, for consideration when implementing a low carb diet. As with all low carb diets,where you are looking to increase fats or protein, you should always take medical advice.
A self confessed low carb food junkie Andrea Simpson has lost over 40lbs on low carb diets. Andrea runs a website, http://www.eatinglowcarb.info, devoted to low carb eating.
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