Which foods should be eaten together

Separate nutrition is a popular concept whose origins lie in Ayurvedic medicine of ancient India. It is based on the idea that there are food products that are incompatible with each other.

If you combine them incorrectly, for example, eat a steak or a burger with French fries, you will face metabolic disorders, digestive problems, fermentation in the intestines, increased gas formation and intoxication of the body.

According to the concept of separate nutrition, all food is divided into different groups – carbohydrate, starchy, fatty, protein, sweet and sour fruits, vegetables, separately melon and watermelon. Sometimes foods are simply divided into acidic, alkaline and neutral. And all these groups, according to certain rules, can or cannot be combined with each other in one dish.

There are many of these rules, here are the main ones:

  • Fruits can only be eaten on an empty stomach, especially melon;
  • Avoid combining protein and starch;
  • Avoid combinations of starch and acidic foods;
  • Avoid combining different protein sources;
  • All dairy products must be eaten separately from other products, especially milk; they cannot be combined with anything.

Other rules include fats should not be mixed with proteins, fruits and vegetables should be eaten separately from each other, and carbohydrates should not be combined with any food groups. The presence of so many rules makes following the principles of separate nutrition a very difficult task, to put it mildly.

All these rules are mainly based on two ideas:

  1. Because different types of food are digested at different rates, combining fast-digesting food with slow-digesting food causes a blockage in the digestive tract, leading to negative digestive and health consequences
  2. Different types of food in the digestive tract require different enzymes to break down, which require different levels of acidity in the intestines to function effectively. Therefore, the body cannot properly digest different foods at the same time.

What does modern science say about this?

Everything that is currently known to modern nutrition science (nutrition) about the basic biochemical and physiological processes occurring during digestion directly contradicts all the principles of separate nutrition. These principles were developed at a time when there was a very vague understanding of how the body works.

First of all, regarding the idea that our body is not adapted to digest different types of food at the same time. The fact is that all food products are a combination of macronutrients – proteins, fats and carbohydrates. For example, vegetables and grains are considered carbohydrate foods, but they also contain protein.

Or meat is considered a protein food, but even the leanest piece contains fat.

Normal growth and development of the human body is based on the assimilation of food containing various macro- and micronutrients, without this we would not survive as a species, and this is what the entire work of the digestive tract is adapted to.

When food enters the stomach, gastric juice and the enzymes pepsin and lipase are produced, which begin to break down protein and fats. Moreover, as studies show  , pepsin and lipase are produced even if the food does not contain proteins or fats.

Then the food enters the small intestine, where the acidic gastric juice is neutralized, and active production of enzymes occurs that successfully break down proteins, fats, and carbohydrates. Therefore, there is no point in worrying that the body will have to choose between digesting, for example, protein or starch. In fact, he is naturally specially tuned to this kind of multitasking.

foods should be eaten together and which should never be combined?

The second principle of separate nutrition states that incompatible foods disrupt digestion, creating an inappropriate acid-base balance (pH) for the effective functioning of different enzymes. It is true that different enzymes require a specific pH to function properly, and that not all enzymes require the same pH.

However, when you eat more alkaline or more acidic foods, it does not significantly affect the pH in your digestive tract. At the same time, the body has several mechanisms to maintain in each part of the gastrointestinal tract exactly the acid-base balance that is necessary for the successful digestion of food.

For example, the stomach always has an extremely acidic environment. When food enters there, the acidity may first decrease, and then acidic gastric juice is released, and everything returns to normal. This is necessary in order to begin the breakdown of protein, activate the production of the necessary enzymes and kill bacteria potentially present in the food.

The small intestine does not need such a high level of acidity, so when food comes from the stomach, an alkali is added to it , which neutralizes the acid, and the pH becomes optimal for the work of enzymes in the small intestine. Even if you eat something too acidic or alkaline, the necessary adaptation will occur and the pH will be where it should be to effectively digest the food. Thus, the body has everything under control and there is nothing to worry about.

Another “horror story” of the concept of separate nutrition, associated with supposedly incompatible products, is fermentation and rotting in the stomach.

What this means is that when you combine a fast-digesting food with a slow-digesting food, the former is forced to linger in the stomach for so long that fermentation processes begin.

However, in reality this simply cannot happen. Fermentation requires the appropriate bacteria, and the environment in the stomach is so extremely acidic that only a very specific bacterium, Helicobacter pylori, can survive there, which can only cause stomach ulcers.

There is only one place in the digestive tract where trillions of bacteria thrive and fermentation actually occurs: the large intestine. Gut bacteria feed on undigested carbohydrates such as fiber and produce intestinal gases as well as beneficial short-chain fatty acids .

In this case, fermentation is something that is very important and necessary for the body. Fatty acids produced by gut bacteria reduce inflammation , improve blood sugar control, and reduce the risk of colon cancer. This also means there’s nothing wrong with the intestinal gas you suffer from after eating – it’s a sign that your good gut bacteria are well nourished.

Scientifically proven examples of the right food combinations

Although the principles of separate nutrition do not have any scientific basis, this does not mean that exactly how you combine foods does not play any role at all. There are quite a few scientifically proven combinations of products that can significantly improve, or, conversely, worsen the digestion and absorption of a particular food.

Here are some examples:

1. Citrus fruits and iron

The iron we get from food comes in two forms: the heme form, which comes from meat and other animal products, and the non-heme form, which comes from plant foods.

Heme iron is well absorbed by the body, but non-heme iron is poorly absorbed. Fortunately, there is  an effective way to increase the absorption of non-heme iron: vitamin C.

If you combine foods rich in this vitamin (oranges, tangerines, lemons, bell peppers) with plant sources of non-heme iron (spinach, legumes, nuts, seeds, dried fruits, cereals), it will be an excellent combination.

Vitamin C, in addition to making non-heme iron easily absorbed, reduces the ability of phytic acid, found in legumes and nuts, to block iron absorption in the intestines.

2. Carrots and fats

Some important nutrients, such as fat-soluble vitamins and carotenoids, require fat to be absorbed by the body.

Carotenoids are plant compounds found in red, orange and dark green vegetables, including carrots, tomatoes, red bell peppers, spinach and broccoli. Research shows that a diet rich in carotenoids reduces the risk of certain types of cancer, cardiovascular disease and vision problems.

However, if you eat these vegetables without adding fat, you may miss out on all these benefits. It’s best to combine carotenoid-rich vegetables with healthy fats like olive oil, avocados, nuts and seeds. It’s also good to add cheese to a salad or butter to steamed broccoli.

3. Spinach and dairy products

Spinach, sorrel, rhubarb, dark chocolate and cocoa, black tea, beets, nuts and berries contain oxalates – substances that bind to calcium and form insoluble compounds. This can, depending on the circumstances, be either beneficial or harmful to you.

For people who are prone to forming kidney stones, consuming calcium-rich dairy products along with foods containing oxalates, such as milk tea, may benefit them by reducing  the risk of kidney stones.

On the other hand, the combination of oxalates and calcium reduces calcium absorption.

For those who eat a balanced diet, this is not a problem , but for those who consume little calcium or eat too many oxalate foods, this interaction can be harmful. If you’re worried your body isn’t getting enough calcium, it’s best to avoid combining dairy products with foods rich in oxalates.

And finally, most importantly, in light of all of the above, is it possible to eat meat and potatoes and cucumbers or herring with milk? The answer to the first question is yes, of course. As for the second, the answer will also be generally positive; from the point of view of the biochemistry of digestion, there are no contraindications to simultaneously digesting milk, cucumbers or herring.

However, if you eat too many cucumbers with milk, it can cause bloating and diarrhea. This effect is due to the fact that cucumbers contain, among other things, fructose, and milk contains lactose. These carbohydrates are broken down by bacteria in the large intestine, producing large amounts of intestinal gas. Therefore, in order to deliver fructose and lactose from the small intestine to the lower sections, a lot of fluid is secreted. Combined with excess gas, this can lead to diarrhea. Therefore, you should not overdo it with cucumbers and milk.