Sparkpeople, the site that I use for keeping track of my calories has a pretty good guide for portion sizes...
The Portion Distortion Guide
A Personal Tracker of Portions in Your Diet
Knowing portion sizes can be just as important as knowing how many portions to eat. The list below includes the number of portions for each food category that are recommended for most people and matches standard SINGLE portion sizes with an easy way to visualize its real size.
Bread, Grains and Pasta (6-11 servings)
1-ounce slice whole wheat bread = index card
½ bagel = can of tuna
½ cup rice, cereal, or pasta = small Walkman
1 two-ounce muffin = cupcake wrapper
1 small roll = yo-yo
1 four-inch pancake = compact disc
1 two-ounce piece of Italian bread = bar of soap
Fruits and Veggies (2-5 servings of both)
1 medium orange or apple = tennis ball
½ grapefruit = car headlight
¼ cup dried fruit = large egg
1 cup green salad = adult fist
½ cup cooked vegetables or fruit = billiard ball
6 ounces of 100% vegetable or fruit juice = hockey puck
1 small potato = computer mouse
1 broccoli spear = two small beanbags
Protein and Meat (2-3 servings)
3 ounces beef, chicken, pork = small pack of tissues
1 ounce of nuts = ping pong ball
½ cup of cooked dry beans or peas = man’s wallet
1 egg = stick shift knob
2 tbsp. of peanut butter = two tea bags
Dairy (2-3 servings)
½ cup nonfat frozen yogurt = child fist
1-1/2 ounces of nonfat cheese = 9-volt battery
1 ounce of cheese = pair of dice
Fats & Oils
1 pat of butter or margarine = Scrabble tile
1 tsp. of butter = tip of thumb to first joint
Snacks and Desserts
1 ounce of chips = medium size handful
1 three-inch piece of cake = small stack of business cards
1 cup of ice cream = baseball
The references are pretty American, but I think it should give you a good idea of sizes...
The current issue of Glamour magazine also had an article on portion sizes - If you're interested I'll scan it in....
