Products containing bad carbohydrates can be classified into two major groups; products with added bad carbohydrates and products that have a high concentration of bad carbohydrates as a result of routine food processing.
Products with added bad carbohydrates.
Over the last 20 - 30 years sugars started to be added to everything. Also a new group of food had arised which is basically comprised mostly of bad carbs, such as chips, nachos, various processed snacks and cereals, they have quickly propagated and resulted in the current epidemic of obesity. Bad carbohydrates are added virtually to all food groups in today's diet. I have been extremely careful to avoid them, and while it is technically possible, it is also extremely difficult, because so many healthy otherwise products are contaminated with bad sugars. I do not think that table sugars, candies and desserts are such a big problem. Everyone knows their danger and they are very easy to recognise. But added sugars are disguised so well that it takes a great effort to identify and avoid them.
Drinks
First we invented sodas and pop, which are essentially a liquid sugar. Then many commercial juices started to have added sugars. Even natural juices without added sugars have unnaturally high concentration of fructose and and other short chain carbs. Fruits are healthy. Processed fruits are not as much.
Dairies with added sugars like sweetened yogurts, sweetened milk etc.
Alcohol in general messes up our metabolism, stimulates an appetite. The problem is even more magnified in sugar containing alcohol mixers.
Processed meat
Many processed meats are comprised of meat with various starches and bad sugars added along with some added preservatives. Processed meat is listed by WHO as a category 1 cancerogen, in the same category as tobacco smoke and asbestos are listed.
Sauces
Most sauces have high sugar content. Sugar containing sauces stimulate appetite and reduce the natural satiety produced by meats. How much chicken can you eat without sauce? Now imagine to add a really good and tasty dipping sauce, all over suddenly you can eat a double portion without much effort.
Salad dressings and salads
Commercially prepared salads often have table sugar literally directly added to them. Most commercially produced salad dressing have significant amount of sugar, read the labels.
Baked products
Baked products have high concentration of natural bad carbohydrates from refined grains, they also often have significant amounts of added sugars as well.
Preserved products
Sugar is often used in many preserved products, sometimes in huge quantities. It is often used as a preservative for various fruits and vegetables. Preservation in general, just think about the idea of preservation from a general prospective, we want to make food to be unattractive for natural bacteria to consume. So, it is not good for bacteria, what about humans? Many commercial soups have starch as a thickener. Dairy products with added sugars or with processed fruits. Cereals. I believe there are should some healthier cereals, I just do not have a simple way to distinguish them from bad ones. Processed food has a separate dedicated next section.
Products that have bad sugars as a result of their processing.
Most of these products are not as bad as added sugars, but this is a very heterogeneous food group. For example white wheat flour or refined grains are worse than a table sugar.
Potato.
Relatively new food group in our diet originated from North America along with other "beneficial" products, like a tobacco. What a coincidence. We can not consume potato raw, but any potato processing results in production of bad sugars. The more it processed, the worse it gets. Baked potato is likely the least harmful. Potato chips is basically sugar shaped in a convenient to consume shape. And guess who is a major consumer of potato starch? It is a processed meat industry.
Corn products
Corn belongs to grains but corn derivatives like chips etc. often resemble potato products in their appearance and health "benefits" as well. Another coincidence of food originating from North America. High fructose corn syrup is the most common added sugar.
Grains and legumes.
Grains are small dried, hard seeds. Two main types of grain crops are cereals and legumes.
Cereals crops are members of grass family. Typical cereals are wheat, rye, rice, oats, barley, corn.
Legumes or pulses are members of pea family. Typical legumes are beans, soybeans, olives, chickpeas, peanuts.
Pseudocereals are starchy grains of broadleaf plants family. They are actually fruits. Common representatives are buckwheat, chia, quinoa, amaranth.
Grains are comprised of outer layer, rich in non water soluable fibers and other beneficial components, germ, which is a tiny baby plant, and endosperm, which is a starchy part intended by nature to be a source of energy for a baby plant.
We are unable to digest grains without processing. There are different ways to process grains and legumes, some of them are more healthier and other are less healthier. When we have more fibers and vitamins preserved, we will call it healthier. When we preserve more of the starchy part and discard the fibers and other beneficial components we will end up with a less healthy product at the end. Refined grains are basically comprised of grain starch with all beneficial healthy fibers and vitamins removed. Originally when refined grains were introduced, some times in the beginning of the last century, the group of people who relied on them as a main source of nutrients started suddenly get sick from significant vitamin deficiency. Enriched white wheat flour was introduced. It is essentially bad carbs extracted from the wheat grains with vitamins added.
In my opinion all grains and legumes have a share of bad carbs depending on the way they are processed. If we remove all of the carbs and just leave the fibers, we would end up with another extreme, this is would be essentially a sawdust without any calories.
There are two ways to deal with grains and legumes from weight management prospective. We can exclude them from our diet completely. This is one of the approaches that followers of lately popular Paleo Diet do. Another option is to select the products made of grains and legumes processed in a proper way.
Oatmeal. Many of the oats processing pathways will make oats to resemble sugar, more than a healthy grain. Instant oats seem to be the worst. Steel cut oats appear to be the healthiest.
Rice is another grain we can not consume raw and it might be a potential source of bad carbohydrates. Instant rice is the worst. In general wild rice is likely the healthiest, followed by brown rice.
Other natural products with high concentration of bad sugars.
Those products may need to be avoided or excluded for people facing weight loss or appetite control difficulties. Sweet or starchy vegetables like parsnips, winter squash, cooked beets and cooked carrots, cooked tomatoes, tomato paste, prepackaged vegetables with sugars. Honey is one of the rare natural products that from weight management prospective is metabolised like a table sugar. See a separate section about processed products.
Desserts
The previous carb metabolism section explains how deserts make us gain weight. It is not that much about calories, but it is about appetite stimulation. You just need to be mindful of the desserts appetite stimulating properties and consciously control how much you eat instead of relying on your inner voice when it comes to desserts.
Alcohol
In terms of its metabolism from weight management prospective any alcohol should be viewed as a "super bad sugar", if you want the baddest of them all, it would be a sweet alcohol or alcohols with added sugars like in many mixers.
Cooking
I am not a follower of raw food diets, but I believe that the only healthy fruits are fresh or frozen ones. I also believe that consuming whenever possible raw and unprocessed/uncooked vegetables is healthier for us in general, especially for weight management.
There is no way to exclude all bad carbohydrates completely from our diet. We have to be realistic, unless we live in a bubble, never go out and never share meals with friends, it is impossible. But we need to know the face of our worst enemy in the fight with obesity. Bad sugars are unhealthy man made food additives and food substitutes which should be avoided at all cost. They provoke our powerful reflex of self preservation to be out of balance, stimulate our appetite and force us to eat more than we need.
I didn’t even touch the topic how bad are bad carbohydrates for our cholesterol, triglycerides, diabetes, cardiovascular diseases, non-alcoholic fatty liver disease etc. It might be a topic of a separate discussion, but believe me – there is no single positive benefit from bad carbohydrates. Exclude or minimise them whenever you can.