Eat fruit for dessert, put jam on bread or mix meat with pasta. These are common mistakes according to food combining theory.

7 food combinations that we should avoid7 food combinations that we should avoid

Last update: May 25, 2024

The authors who defend these nutritional precepts establish that some foods cannot be mixed in the same meal. The reason is that if they are consumed at the same time they are not digested well and this has an impact on health problems.

Although these are theories that are not scientifically based, many people decide to follow this type of diet. Find out all the banned pairings below.

What do we understand by food combination?

The idea of ​​associating or separating certain foods to improve health has its origins in practices as ancient as Ayurveda. But it was not until the late 1800s and early 1900s when authors such as Herbert Shelton and William Howard Hay laid the foundations for what we know today.

To be able to put it into practice, foods are separated into different groups:

  • Fats: oils, olives, coconut, avocado, margarine and butter.
  • Proteins: legumes (beans, lentils, chickpeas, beans); nuts and seeds (seeds, sesame, flax, walnuts, hazelnuts, almonds, cashews); meat, fish, eggs and dairy.
  • Starches: rice, millet, wheat, bread, pasta, quinoa, oats, potatoes, sweet potatoes, cooked carrots and pumpkin.
  • Vegetables: green leafy (lettuce, cabbage, chard, spinach, kale) and non-starchy vegetables (broccoli, bell pepper, zucchini, eggplant, cucumber, celery).
  • Fruit: sweets (bananas, dates, dried fruits, papaya, figs, grapes); semi-acids (apple, pear, mango, cherries); acidic (lime, lemon, orange, grapefruit, pineapple, strawberry); and melon.

Once classified, some associations of foods are established that cannot be mixed or eaten together. According to its postulates, doing so can lead to digestive problems, generation of toxins, fermentations and various health complications.

The explanation behind these effects is that the stomach needs different times, enzymes and pH to digest different foods. And eating them together hinders this normal gastric functioning.



What are the foods that cannot be mixed?

According to food pairing theory, there are 7 harmful pairings that cannot be made in meals.

1. Starches and acids

Acidic foods reduce the action of the enzyme ptyalin, which is essential for breaking down starches into glucose (another simpler sugar that the body can use). In this way, carbohydrates do not start their digestion well and the body uses much more energy in this process.

Examples of foods that cannot be mixed

  • oat flakes with strawberries, oranges or pineapple
  • pasta, potato, rice, bread (among other grains) with vinegar or tomato

2. Starches and proteins

Starches require an alkaline environment in the stomach. And when proteins are ingested, the juices that are secreted are acidic. Thus, starches remain in the stomach longer and fermentations appear.

Examples of foods that cannot be mixed

  • Bread with jam
  • sushi salmon
  • chicken with potatoes

3. Proteins and proteins

Each of the protein sources requires different digestion times. So when they are ingested in the same meal, their decomposition process is difficult.

Examples of foods that cannot be mixed

  • chicken with shrimp
  • “sea and mountain” type rice
  • squid stuffed with meat
  • chickpeas, beans or lentils with meat

4. Proteins and acids

Acidic foods are not good friends for digestion and cannot be combined with proteins. A stomach environment with a very low pH hinders the function of pepsin (enzyme responsible for breaking down proteins) and the entire protein digestion process.

Examples of foods that cannot be mixed

  • chicken or salmon with orange or lemon
  • meats and fish with tomato or tomato-based sauces

5. Proteins and fats

Foods with a lot of lipids cause a delay in the secretion of gastric juices. In this way, digestion becomes much slower and more difficult.

Examples of foods that cannot be mixed

  • tuna with avocado
  • meat or fish with butter
  • lentil or chickpea salad with avocado

This bad food combination can be “saved” by adding abundant vegetables. Vegetables counteract the negative action of fats on digestion. The compensatory effect is higher with raw vegetables.

6. Sugars with proteins and sugars with starches

All products in this group (sugar) have their digestive action in the intestine. If they are mixed with proteins or starches, the sugars are retained in the stomach and produce fermentation.

Examples of foods that cannot be mixed

  • bread and toast with jam
  • bread made with raisins or dried fruits
  • rolled oats or breakfast cereals with honey or syrups
  • sponge cake doughs with egg, milk, flour and prepared with honey or sugar

7. Fruits with any type of food

All fruits are digested at a high speed and, in combination with other foods, are retained in the stomach. For this reason, they recommend separating it an hour and a half or two from meals.

Therefore, it is not advisable to use fruits to cook meat or fish. Also do not mix with dairy products (such as yogurt with fruit or smoothies with milk).

There is only one exception to this last rule. Green leafy vegetables can be eaten with fruits, since they have similar digestion times. These are, for example, common ingredients in a wide variety of green smoothies.

What fruits can’t be mixed?

Melons cannot be combined with any other fruitsince its digestion is the fastest of all.

In addition, Sweet and sour fruits cannot be eaten at the same time. We remember the specimens of each group to be clear about which ones should be ingested separately:

  • Acidic: pineapple, strawberry, lemon, orange, grapefruit, lime
  • Sweets: dried fruits, figs, grapes, dates, banana, persimmon, cherimoya

Favorable food combinations

Contrary to what we have just seen, There are mixtures that can be made. This is because some foods do not interfere with the digestion of others. Specifically, we are talking about two permitted groupings.

On the one hand, Non-starchy vegetables can be combined with almost any food. The only exception is fruit, which only pairs well with green leafy vegetables (chard, spinach, lettuce, kale et al).

In second place, starches of different natures can also be digested well if eaten together. In this case, it is best to accompany them with vegetables such as broccoli, asparagus and green leaves.

Examples of favorable combinations

  • broccoli with salmon
  • vegetable omelettes
  • vegetable soup with noodles and rice
  • rice with zucchini, eggplant and pepper
  • sauteed asparagus and zucchini with chicken
  • green smoothies with chard or spinach and fruits
  • vegetable salad with legumes, rice or pasta


Is it healthy to eat this type of diet?

In recent years, diets based on these postulates have experienced certain boom times. Therefore, it is normal to wonder if its application is positive or harmful to health. Without going into specific cases, it can be said that it is a valid way of eating. (as long as there are no health conditions that discourage it).

However, At the moment there is no data to support their claims. It must be taken into account that the stomach is prepared to digest different foods at the same time. Although you need enzymes, times and a different pH for each of them.

It also cannot be assured that eating the food groups separately has health benefits. Many people decide to follow food combining to lose weight, improve digestion and other minor ailments. But none of this has been proven with studies.

And, although it does not seem like a harmful diet, Yes, it has some important limitations. which, in the long run, can have a negative impact on well-being:

  • It is a difficult diet to implement, especially in the long term.
  • There are difficulties when it comes to linking food with social life and meals outside the home.
  • It can lead to nutrient deficiency if, due to these complications, people eat less food than they need.
  • It is possible that, over time, boredom may appear if you do not look for varied and attractive recipes and ways to present dishes.

What is the best combination of foods for a balanced diet?

For all those people who are looking for a way to eat healthy and easy to carry out, It is possible to make balanced menus by associating the main food groups.

To do this, the main meals can be planned as follows:

  • Half of what you eat (approximately) has to be vegetables (Together with fruits, they are foods with many benefits). They can be served in salads, vegetable creams, stews or roasts.
  • A serving of proteinwhether of animal or plant origin: legumes, tofu, fish, eggs or poultry.
  • Another serving of carbohydrates, which can be a little lighter or smaller at dinner. You can vary between pasta, rice, oatmeal, bread, potatoes, millet, couscous, etc. It is always better to choose whole grain varieties.
  • Some healthy fat sources to season or complete meals: olive oil, olives, cheese, avocado, nuts, seeds.
  • A yogurt or a piece of fruit for dessert.

In this case, there are no restrictions on foods that cannot be mixed with each other. However, Individually, combinations that cause discomfort or digestive problems can be avoided..

Combining foods has no more benefits than other healthy diets

Basing your diet on this theory does not have to be bad in itself. As long as the diet provides all the necessary energy and nutrients, does not burden the person, and is not contraindicated for health reasons.

However, Nor can it be said that it has additional health benefits. In principle, the body is prepared to process foods that, in theory, cannot be mixed. So the most advisable thing is that each person can combine the foods that suit them individually.