Decoding food labels can be a real challenge for consumers, but understanding them is key to making healthy and informed choices. Here's a little guide to help you out:

1. **Nutrition Facts**: This is usually a box or panel that provides information on serving sizes, calories, and nutrients. Pay attention to serving size as it's important for understanding how much you're actually consuming.

2. **Ingredients List**: Ingredients are listed in descending order by weight. The first two to three ingredients are the most significant. Watch out for high amounts of sugar (which can be listed under many names, like high fructose corn syrup, sucrose, dextrose, etc.) and unhealthy fats (like trans fat or saturated fat).

3. **Percent Daily Values (%DV)**: This tells you how much of a nutrient is in one serving of the food. Try to get 100% of each nutrient every day. If it's 5% or less, it's low for that nutrient; if it's 20% or more, it's high.

4. **"Organic" Label**: Food labeled "organic" is produced without synthetic fertilizers, radiation, sewage sludge, or genetic engineering, according to the USDA. However, only those with "100% organic" label are completely organic.

5. **"Non-GMO" Label**: Non-GMO means a product was produced without genetic engineering and its ingredients are not derived from GMOs.

6. **"Natural" or "All Natural"**: This phrase is not strictly regulated. It generally means the product has no artificial ingredients or colors and is minimally processed, but details can vary.

7. **Calories**: This number tells you how much energy you'll get from one serving of the food. Consider both this and nutrient content to get a sense of a food  s health value.

8. **Claims like "low fat", "reduced sodium" or "light"**: These phrases are regulated by the FDA and have strict criteria. For example, "low fat" foods must have 3 grams of fat or less per serving.

9. **"Best Before" and "Use By" Dates**: These dates refer to quality and safety. "Best before" speaks to when the product will be at optimum freshness, while "use by" is the last date recommended for the use of the product.

Remember, don't just focus on one single thing like calories or fat. It's important to consider the overall nutritional profile including fiber, protein, sugar, and vitamin content when making choices.

Yes, there is a difference between "Organic" and "100% Organic" labels, and it's based on the regulations set by the United States Department of Agriculture (USDA). 

- **100% Organic**: This is the highest level of organic certification. This label is used on products that are completely organic or made of all organic ingredients. They are free of synthetic additives like pesticides, chemical fertilizers, and dyes, and have not been processed using industrial solvents, irradiation, or genetic engineering. Strict regulations are in place to ensure agricultural products meet this high standard.

- **Organic**: If a product bears the "Organic" label, it means at least 95% of its ingredients are organically produced (excluding water and salt). The remaining 5% can be non-organic agricultural products that aren't commercially available as organic, and/or non-agricultural products that are on an approved list. 

Products with either label are allowed to display the USDA organic seal. 

Remember that these standards can vary somewhat from country to country, but the principle remains the same - "100% Organic" ensures a completely organic product, while "Organic" indicates a high percentage of organic ingredients.

Sure, regulations for "100% Organic" products are very stringent. They do not permit the use of any synthetic additives. Here are some of the common ones that you will not find in "100% Organic" products:

1. **Synthetic Fertilizers**: These fertilizers are derived from synthetic compounds. They're created in industrial conditions and are intended to deliver nutrients to plants quickly. Examples include Ammonium Nitrate, Superphosphate, and Potassium Sulphate.

2. **Synthetic Pesticides**: Synthetic pesticides are a wide-ranging category of synthetic chemicals designed to kill or control pests, insects, and disease-carriers. Examples include Malathion, Glyphosate, and Permethrin.

3. **Artificial Preservatives**: These are chemicals added to foods to prolong their shelf-life and maintain quality. Examples include Sodium Benzoate, Potassium Sorbate, and Sodium Nitrite.

4. **Artificial Colors and Dyes**: Synthetic or manmade colors used to enhance or alter the color of food and drinks. Examples include Red 40, Yellow 5, and Blue 1.

5. **Artificial Flavors**: These are chemically made flavors that mimic natural flavors. They are created in a lab by food scientists and can be found in a variety of processed foods.

6. **Artificial Sweeteners**: These are sugar substitutes that can be chemically manufactured. Examples include Aspartame, Sucralose, and Saccharin.

7. **Genetically Modified Organisms (GMOs)**: GMOs are plants or animals that have undergone a process wherein scientists alter their genes with DNA from different species of living organisms, bacteria, or viruses to get desired traits such as resistance to disease or tolerance of pesticides.

8. **Certain Processing Agents** - Chemicals used during processing, such as bleaching agents or other substances that may affect the final product  s additives and nutrient composition.

The aim of excluding these from "100% Organic" products is to produce food that is natural, minimally processed, and free from harmful chemical residues or alterations. Products with this label promote a cleaner and environmentally conscious method of farming.