Macronutrients

Carbohydrates

There is no such thing as an essential carbohydrate, in fact, the body will survive, albeit miserably, without carbs of any sort! My biggest pet peeve when it comes to carbs is that I still see and hear the terms 'simple' and 'complex' carbohydrates a lot. 'Simple' and 'complex' carbs no longer mean what you might think!

It has been years since this concept has been disproved, but people, and some magazines, still stick to it (though I do notice a trend towards different foods being considered complex, i.e. before they said potatoes were complex, now they say sweet potatoes, which are in fact better).

Here's what some considered to be simple carbs: sugar(sucrose), fructose(fruit), and lactose(in milk). Complex carbs were: (whole-grain) bread, pastas, potatoes(starches), and vegetables. The new measure used is the glycemic index, and it is a measure of how much your blood glucose levels increase after eating a certain food, basically exactly what 'simple/complex carbs' was meant to address.

Here is how the new thinking (glycemic index) compares to old thinking (complex/simple):sucrose is still not great, but better than most potatoes and some breads and pastas, fructose is probably the most 'complex' carb, as it results in the lowest blood glucose level. So as you can see, we must rethink what simple and complex carbs are.

Fiber is probably the most talked about nutrient in most dieting circles these days. There are two types of fiber: soluble and insoluble. Soluble is said to slow down absorption from the small intestine, and insoluble partially ferments and affects bowel habit. However, how carbohydrates were determined to be either were not very accurate, and this may be redefined in the future as well.

Ingesting any fiber greatly reduces the glycemic index of any food you eat, which is why you should eat lots if you're trying to lose weight. I believe I have seen the RDA of fiber to be around 30-40 grams a day. If you look at how much fiber is in the foods you buy, that's a whole lot of fiber. Processing strips way to many valuable nutrients out of food, including fiber, so try to stick to fresh vegetables and fruit, beans, and whole grain breads.

For a really complete discussion of carbohydrates, have a look at this article from some 'carbohydrate symposium' in Athens. It's really thorough, and if you want the whole story about carbohydrates from the source, check it out! Carbohydrate in Human Nutrition

Debunking Carb Myths

All sugars/starches are converted to glucose before being stored as fat!
Starches are converted to glucose more readily than fructose/lactose.
Fructose(fruit)/Lactose(milk) are simple in structure, but act more complex than any starch!
Fructose is absorbed via 'active transport', which requires energy, burning calories.
 Bottom line, starches (potato, bread, rice, pasta) are 'simpler' than simple sugars lactose, fructose, and even sucrose!! If you don't believe me, get a blood glucose meter(or Keto-Stix), eat a potato, wait a half hour, measure your blood glucose, and do the same after eating 2 apples. Or just trust me, or look up any glycemic index site!

Protein

Protein is absolutely necessary for building muscle. Amino acids, the constituents of proteins, are the building blocks for everything in the body like cells and enzymes. It also serves as a minor energy source for the body. Properly planned consumption of this nutrient is essential!

How much to consume?

The generally accepted measure is one gram of protein per pound of lean body mass, though I have heard as much as 2 grams (trust me, stick with 1). This is a lot higher than for inactive people, because not only are we trying to grow new muscle, but we want to prevent muscle we already have from breaking down. With the increased energy demands of an active lifestyle, and especially during calorie restricted diets, the body will catabolize muscle tissue for energy. To avoid this, you must maintain a positive nitrogen balance. So here's a quick word on nitrogen retention.

Nitrogen Retention & When to consume

The body always resorts to using some amino acids for energy, and if you don't have any floating around your blood, it'll go to your muscle, and break it down to meet its requirements. Obviously this is very undesirable. To avoid this, you should consume protein every 2-3 hours.

When you go to bed you are without food for over 8 hours, and all the amino acids in your blood are used up, so at some time in the night you reach a catabolic state. Some guy's will even go so far as to wake up at 4AM to have a protein shake. Though this is a bit extreme, you should make an effort to consume a good deal of protein first thing in the morning to stave off any further muscle wasting.

I have read that you should drink an easily absorbed shake before bed for best results, but to me this seems counter-intuitive, and I can't help thinking it's an attempt to sell more supplements. My thoughts are that before you go to bed you want consume some kind of protein that is digested slowly. This way, you absorb aminos from your gut for the next couple of hours, so that your body doesn't go catabolic till as late as possible. Kinda like a time release formula!

Probably any kind of meat, or even nuts would be a good choice for this. But since both can be high in fat, especially nuts, you should eat no carbs with this last meal, as this would cause insulin release. Insulin means fat storage, especially since you go to bed and are inactive. In the morning, you want a protein source that is absorbed as quickly as possible, and this is where I would definitely recommend protein shakes as being the best source.

Many people expound the benefits of a post-workout shake high in protein to supply your body with amino acids for muscle repair. True, a post-workout shake can bring great gains, and I highly recommend them. But I also think it is important to consume some protein about an hour before working working out.

The reasoning is this, after ingesting protein, it takes a while to digest and enter your blood stream. Eating protein before working out puts aminos in your blood for immediate use. These aminos can be used to rebuild muscle right away, as well as spare your muscle from being broken down for energy. Branched chain amino acids (BCAA's) may be best for this (lots of them in whey protein) as they are the first aminos broken down for energy during heavy exercise.

Which protein? Amino Acids?

When choosing food sources for protein, one of the most important things to remember, especially if your a vegetarian, is that most plant sources are incomplete. The body can synthesize many amino acids from others, but there are 10 amino acids that are essential. Combining vegetarian sources can ensure all amino's are covered. Another factor is bio-availability.

When discussing the quality of protein sources, reference is often made to bio-availability, or biological value (BV). This is a measure of how easily a protein source is assimilated and utilized by the body. If this means you still use all the protein but more slowly, or it just passes through your system, I don't know. I suspect it is the former. Here is a list of various protein sources and how they compare. The higher the better:
As mentioned before, whey is a great source of branched chain amino acids (valine, leucine and isoleucine), which could also be purchased separately. BCAA's are important to reduce muscle wasting, and have been proven to be quite effective, though maybe not necessary if your consuming whey.

Glutamine is another amino acid that has been getting a lot of attention lately. It is found in high concentrations in muscle tissue, and supplementation may lead to greater muscle tissue synthesis. Glutamine also plays a role in reducing muscle catabolism.

For a complete discussion of amino acids see this awesome site that tells you what each amino acid is used for, how it is synthesized, everything. So check out this Amino Acid Glossary.

Fat

Fat is essential to many bodily functions, and cutting fat out of your diet can result in some pretty ugly symptoms such as hair loss, and in the extreme case, death.Do not cut fat to less than 15% of your total calories!. There are three types of fats: mono and polyunsaturated fats, and saturated fats.

The body can synthesis many of the fatty acids it needs, but it cannot synthesis linoleic and linolenic fatty acids (omega-3 and omega-6). These must be ingested in the diet. One should attempt to consume at least 10 grams of essential fatty acids a day.

Linoleic is fairly common and can be found in many vegetable oils like walnut, olive, rapeseed, and safflower oil. Most nuts also have a fair amount of linoleic acids, and due to their high fiber and magnesium content make an excellent snack!

Linolenic is far more difficult to find in foods, and if you suffer from a deficiency, it would be of this fatty acid. The best sources with ideal ratios of both fatty acids are flax oil and hemp oil. Another great source is cold water fish such as salmon.

After being digested, fat is absorbed into the system as fatty acids which can be either used for energy or building blocks of enzymes and the like. Excess fatty acids are stored in adipose tissue.

Fat absorption into the blood follows a much different path from carbs and protein. Afer ingestion, dietary fat may be released into for the next 5 hours or more.

Fat storage in the adipose tissue is greatly enhanced by the presence of insulin which is why a fatty meal should never be eaten with, or followed by a meal with lots of carbs or high glycemic index. Some say fat storage require a threshold insulin level to be reached, meaning if you always ate low GI foods, no fat would get stored. Not likely!!

I'll do some more research into fat digestion, absorption, requirements, and storage and add it here as I get it!