If you are interested how to get your healthy appetite back and there is only one chapter you want to read, this should be the one.
Up To Date 2017 (one of the official evidenced based publications for Internal Medicine physicians):
"Widespread promotion of low-fat diets in the 1980s and 1990s led to a reduction in the percentage of calories from fat in the United States diet and a concurrent increase in carbohydrate intake. Despite these dietary changes, the prevalence of obesity and type 2 diabetes mellitus continued to rise. Perhaps partly due to unsatisfactory outcomes with low-fat diets, a large segment of the population that wants to lose weight is increasingly following many popular diets that emphasize low- or no-carbohydrates for weight loss.
In the scientific community, serious concern has also been raised over dietary recommendations for high-carbohydrate, low-fat diets. High-carbohydrate diets reduce high-density lipoprotein (HDL) cholesterol and raise blood concentrations of glucose, insulin, and triglyceride and blood pressure, contributing to a now well-recognized metabolic profile called insulin resistance syndrome that is conducive for the development of coronary heart disease (CHD) and type 2 diabetes mellitus."
I will try to simplify this topic as much as possible. Most healthy diet guidelines recommend around 50% of calories to be derived from healthy carbohydrates. There are good, or healthy carbohydrates, and there are bad carbohydrates. Most of the discussions on this page will be dedicated to bad carbohydrates.
Good carbohydrates are all unprocessed carbohydrates of natural origin and some man made carbohydrates with low Glycemic Index (see below). Processing of fruits and vegetables often results in generation of bad carbohydrates or sugars for simplicity. Many, but not all, manmade carbohydrates are bad. They are usually but not always comprised of short chain sugars. They are often extracted and concentrated from processed fruits and vegetables. After extraction and concentration they are usually shaped as crystals, liquid or syrups which may be consumed alone, but more commonly added to other products.
What is so bad about bad carbohydrates and what makes them different from good ones?
1. They stimulate appetite.
2. They are close to 100% man made,they are addictive, they alter our metabolism
3. They are metabolised differently from natural carbohydrates, which results in fat deposits and increased appetite.
Not everyone who drinks alcohol becomes an alcoholic. Not everyone who eats bad carbs gets obese. But the only way for alcoholics to stay well is to stop drinking. The only way for overweight people to have a successful fight with obesity is to recognize and acknowledge bad carbohydrates. Some bad carbohydrates are easy to identify, but the main challenge is to identify the hidden bad carbohydrates that penetrated every single food group in our diet.
Right from the beginning I want to clarify that it is practically impossible to have them completely eliminated from our diet and I do not think we need to go for such extreme approach. But I think all of us need to learn what and where they are so we can address them properly.
Natural carbohydrates are released into the blood stream slowly sustaining steady serum glucose level and resulting in satiety.
Bad carbohydrates are released and absorbed into the blood stream rather quickly, causing serum glucose to go up suddenly, which results in a spike of insulin that drives this glucose into the glycogen stores, and after they are full, into fat tissue for future use. The resulting hypoglycemia causes hunger and motivates us to crave for more sugar.
Glycogen stores.
Only around 2000 calories can be accommodated in glycogen stores (100 g of glycogen in the liver and around 400 g with a skeletal muscles). 2000 calories is roughly a daily calorie requirement for an average person. In other words it takes around 24 hours starvation to have our glycogen stores completely depleted. Athletes might have them depleted faster. So, unless you are a marathon runner at finish line or starving, the glycogen stores are usually just partially empty. So, after the first few bites, bad carbs are heading directly into the fat deposit stores for future use. Athletes and hyperactive kids deplete these glycogen stores regularly, which partially explains their resistance to fattening effect of bad carbs.
Bad sugar > high serum glucose > high insulin > glycogen > fat > low serum glucose > hunger > eat more sugar
Remember that bag of chips (1200 calories) or box of chocolates that you can not stop eating, and the more you eat, the more you crave. It is not because it tastes so good, it is because these sugars instead of fulfilling us are being literally pumped from our mouth into the fat reserves, lowering our serum glucose and making us hungry along the way.
The harm here arises not from calories, as digestion of any carbohydrates, whether good or bad, produces the same 4 calories per gram as proteins digestion does, which is still twice less than 9 calories per gram produced by digestion of fatty acids. But it is about the way bad carbohydrates are metabolised and resultant effect on our satiety and fat deposits.
Insulin is a growth hormone, and it does exactly what growth hormone sounds like, it makes our body to grow, and for adults it usually happen in horizontal plane.
To summarise, the net result of bad carbohydrates consumption is a prompt deposit of consumed energy as fat and stimulation of appetite motivating us to consume more. Sugar is the most addictive and appetite stimulating chemical. It is of natural source, but it is mostly man made. The most extreme natural equivalent of bad carbohydrates I know is honey. Honey bees did a "human" job and extracted, concentrated and preserved short chain natural carbs along with healthy honey components. Other healthy honey components are healthy, but honey sugar is not, it is very similar to table sugar. Honey was never intended for humans and protected from us by painful stings.
I think when bad carbs are presented as sugars, candies, or chocolates, it is not a big deal. We all recognise them. All of us subconsciously know that this is a treat and that we need to exercise some self discipline as adults and have to impose some control on our children, so we would have at least an illusion that we somehow might influence and control over them. Most of the time we are able consciously control our sugars consumption within the reasonable limits without any adverse health consequences. The problem here is that most of the time we consume these bad sugars without realising that. Our appetite is not natural anymore, it is constantly being distorted by these bad manmade carbohydrates. Hunger is one of the most powerful self preservation reflexes we posses, and it takes a conscious effort to overcome it. Remember what I promised in the beginning? To get back the healthy appetite.
You might think - it does not apply to me, I eat only healthy home made food, there are no added sugars there. Wrong. (:)). Bad sugars are in various proportions everywhere. Any thermal, mechanical or chemical plants processing will inevitably result in generation of bad carbs. We may extract and concentrate them as sugars (more harmful). We may just consume them as a part of the prepared meal (less harmful). In other words there are bad sugar that are physically added to food, and there are bad sugars resulting from food processing. It is impossible to have zero of bad sugars in our diet. We can not exclude them completely, but we should learn what they are, so we can either minimise them or consciously counteract their affect on our appetite.
Let's look closer. Take a carrot and eat it raw, it is full of good carbs. Now process it, boil it, bake it, fry it. Now you have a processed carrot full of bad sugars. Take a wheat seed. Now grind it and bake it, grinding removes fibers, baking splits the starches in short chain carbs, now you have a white wheat flour, a substance which is absorbed into the blood stream faster than a glucose. Those are examples of bad sugars originated from mechanical or thermal food processing. Or take a healthy fish, make it breaded and you have a share of wonder processed wheat added there, plus add a little ketchup, which basically a sugar syrup with some thickeners and flavors. This is an example of added bad sugars.
In other words science about appetite is a science about bad carbohydrates. I think it is not about complete abstinence from bad carbohydrates, but it is about minimising them or dealing with them.
Glycemic index.
Healthy natural carbohydrates are often either long chained, as in vegetables, or bound to other components and fibers, as in whole fruits. They are released in the blood stream slowly, without significant insulin spikes. If the speed of absorption for a glucose is 100, then a speed of absorption good carbohydrates is usually around 20-50. This number is called a glycemic index. This is one of the ways to judge which carbohydrates are more likely to be good or bad. Low glycemic index is 55 and below, intermediate is 56-69, and high is likely 70 and above. Here is the link to diabetes.ca. This glycemic index number could be easily found over the internet. White wheat bread has a glycemic index of more than 100, meaning it is absorbed in the blood stream even faster than a table sugar.
Up To Date 2017: "...a study in which partially pancreatectomized rats were given diets with identical nutrients except for the type of starch (either high or low GI) found that rats given the high-GI food had almost twice the body fat of the rats given low-GI food after nine weeks"
Twice the body fat with identical nutrients other than bad versus good carbohydrates. This is significant, it was observed while they were consuming not just the same amount of calories, but also the same amount of carbohydrates as well, with only difference of bad versus good carbs, like table sugar versus vegetables. Calories are important, but the type of calories makes a big difference as well. The limitation of this study is that it was performed on partially pacreatectomized rats, in other word they had artificially simulated type 2 diabetes.
I think it is possible to lose and maintain weight by calorie restriction alone, but I think the ideal approach should be a combination of proper calorie control along with proper type of products. In other words the key to successful weight management is eating the right food in the right amounts. Another very important moment here is that eating the right food will not only help to manage our weight more effortlessly, but, what even more important, it will prevent or slow down the development of multiple medical problems, which is our ultimate goal.
So, the next chapter is all about bad carbs containing food.
P.S.
Like many others, I was always convinced that there is should be something in food to cause the unexplained epidemic of obesity affecting us. It can not be explained by genetic factors or environment alone. For very long time I was thinking that it was related to hormones or antibiotics used in farming industry. Now I think I have found this enemy. I am entirely convinced that it is caused by added sugars. Not as much by bad carbs originating from common culinary food processing, as we've been doing that for centuries. The consumption of corn fructose has multiplied over the last few decades. In the United States, high fructose corn syrup sweeteners were not commercially available until 1960s, but now comprise more than 20 percent of total daily carbohydrate intake and 10 percent of daily total energy intake, representing an increase of more than 2100 percent. If you believe you might be spared from such, do not full yourself. Sauces, juices, crackers, salad dressings, restaurant salads, commercial soups, processed meats, breaded food, and the list goes on and on and on. Try to read a label on any packaged food. Are you sure that you understand the meanings of the words describing different components?
In my opinion many children, teenagers, and likely many young adults in their 20s, also athletes have very different relationship with sugars than grown ups and what I call "usual middle aged people" like myself. They burn tones of calories, they deplete their glycogen stores and they need a lot of energy supply to recharge their glucose rechargeable battery.. But when they face weight management problems, the above rules apply to them as well.