For those watching their weight and nutrition and interested in Wine and Health in general, this is the first in an installment of my interpretation of the current science fact and fiction. I neither vouch for nor deny the accuracy of these statements (for the lawyers), but I believe them to be true.
Data are using a typical Cab red wine which I prefer and has the most health benefits.

Wine Nutrition 101-
Prerequisites: High School Math; Having had a bottle of wine before; Being a Vinocellar member

The real basics
Terms-
-1 ml= 0.034 fluid ounces (oz)
-1 750 ml bottle =25.4 fluid oz. This is 6.2 or for practical purposes =~6 typical 4 oz glasses wine. 1 glass as defined below is ~120 ml. Thus there are 6 glasses in one bottle. Moderate drinking is defined as 1-4 glasses/day. Heavy drinking is defined as 1-4 bottles/day. No drinking is...you get the point
-% Volume/volume amount alcohol equivalency is in : 1 mug beer (4%)=1 4 oz glass wine (12%)= 1 1oz shot spirits(50%). So Joe 6 pack drinks the equivalent of 1 bottle wine in alcohol per setting.
-for the typical red wine-the bottle is 12%alcohol ( and thus 88%water) and ~0% other. The typical range is 8-16%.

-Wine Density
The density is a component mass in weight divided by it's volume. The density of water is 1 kg/liter or 1 g/ml. Wine's density varies since it contains some though minimal solids which increases density v/v water, and also contains alcohol which decreases density some v/v water.
-The term specific gravity is more appropriate since it compares the wine weight to a pure water reference standard, creating a normalized ratio. A bottle of water has a specific gravity of 1. Wine may be more or less, but not that much, usually 0.8-1.2. For a dry red, specific gravity wine at 60oF =0.98 , or essentially ~1.
-The term must density (or weight) is more useful to winemakers since it gives a measure of grape ripeness by components dissolved in the must. Since ~90% are reduceable sugars, this is a measure of potential alcoholic strength as well. The French use the scale Baume( equivalent to %alcohol volume/volume). The USA and Oz use the Brix scale (weight/volume), and the Germans use the Oeschele scale (weight/weight or the number in thousandths of the specific gravity eg 1.090=90 Oeschele). That just about describes the number of viewpoints in NATO these days.
Since each % alcohol derives from a known quantity of sugar, nomogram scales can be made to compare these.
Basically
9 Baume= 16 Brix=65 Oeschele=8%alcohol
13 Baume=22 Brix=95 Oeschele= 12%alcohol
14 Baume=26 Brix=110 Oeschele=14%alcohol
15 Baume=28 Brix=120 Oeschele=15%alcohol
Vinocellar members, keep this chart with you at all times.

The Caloric Content
Calories are the energy measured in heat given off when a substance is completely used as fuel. Foods have caloric content; traditionally, this was measured by bomb calorimeters where a weighted amount of a food is first ignited in a sealed water container and the surrounding rise in water temperature measured.
A Calorie=kilocalorie= is the heat required to raise 1 kilogram (=1 liter) of water 1oC. Both 1 gram of sugar or 1 gram of protein yield 4 calories; 1 gram fat yields 9 calories;1 gram of ethanol yields 7 calories.

Thus the bottle vitals in a good red are approximately:
-660 g water
-90 g ethanol
-9 g glycerol
-1.5 g residual sugars
-0.5 g proteins nitrogen
which throws off your diet to the tune of ~710 calories or almost~120 calories per 4 oz wine glass or 105 cal/3.5 oz glass. For comparison, a 12 oz beer suds up 150 cal, a shot of Tequila 110 cal, and a wine cooler [ who drinks these anymore?] 210 cal. For the party crowd who like sweet mixed drinks, add up to 50-80 more cal per mixed drink to a baseline shot. Yikes!!

For the weight watchers in the crowd, that single 4 oz glass wine with dinner comes out to:
=2 1/2 slices bacon=1 ice cream cup= 3/4 frankfurter=1/2 bag popcorn=1/2 3 oz hamburger=2/3 a slice of pizza (NY size Famous Rays 14 " divided in eighths, of course).
This is also =2 cans of chicken noodle soup=1 nondiet cola=1 brownie=1 plain doughnut.
Surprisingly, this is also = 1 6 oz glass pure grape juice and 2 cups of seedless grapes.

There is also :
-2.5 g acidity, nearly equivalent tartaric, lactic, and succinic. The first is the strongest and most resistant to degradation. The pH of a dry red wine is ~3.5. This will dissolve your teeth over time( if you fall asleep in a pool of wine). Not recommended. Of course, it will stain them first with the anthocyanins.
In fact, only our stomach with a pH of 2 can provide the environment to neutralize the acidity of wine. If you have reflux into your esophagus from your stomach, the alcohol (and mixed stomach acid) burns the lining wall causing esophagitis, which is perceived as heartburn. Ouch! This is why doctors tell people with this problem to stop drinking.

-0.3g salts, or minerals, often also called ash, since it remains as solid residue after combustion, mostly potassium (~.1g); 60 mg Calcium; 25 mg Iron, and 120 mg Magnesium.
Overall this is a salt concentration of 0.35% N (N=Normal).
The human body is 0.9% or 3 times as salty. Fresh water varies but is around 0.2%. Pure water is 0%If you left your finger in the glass while you fell asleep, your skin would prune, take in water, and turn nicely purple. Not recommended.

-3g (poly)phenols, 80% of which are tannins. From a health perspective, this is all that counts really. Green tea is more effective but can't give you the buzz to ask your date to come back to yuor apartment for a round of Twister.

-and not to be left out, the vitamins(vital amines) iin microsopic amounts
0.1 mg Vit B1(thiamine)
0.2 mg Vit B2(riboflavin)
0.5 mg Vit B6(pyridoxines)
2mg Niacin (nicotinic acid)
0.0002mg Vit B7(biotin)
0.0001mg Vit B12 (cobalamin)
1 mg CoA precursors (pantothenic acid)
These meet roughly 7% of the minimum RDA, or are acquired akin to biting off 1/10 of a Flintstone child vitamin. If you drink for a living, you may want to take your kids' vitamin bottle to keep up at the gym. Not recommended.

So you want a bottle eh?
Well, with wine nutritionally, we have a teeth staining and dissolving fairly caloric nutritionally vapid vessel of fermented fruit in near fresh water. From a dietary perspective, this is a disaster!!! If this is all you drank, ou'd get a Darwin Award. This is why man invented dining.

But thank god, this is not the end of the story. (Hint:remember the tannnins)
No it is only the beginning

--------------------
DrT