Protein diet: menu, benefits and contraindications

Everyone has heard of the high-protein diet. Although this diet has generated considerable controversy and debate in nutrition and health circles, it has remained quite popular for many years. Some use it to lose weight, while others use it as an effective tool for achieving fitness goals. In this article, we've tried to gather comprehensive information about the high-protein diet: what it is, how it works, the basic principles of nutrition, and its positive and negative aspects. We'll offer you a sample menu for a week and also give you tips on how to avoid health problems and maximize the benefits of a high-protein diet.

What is protein and why is it important for the body? 

Protein, the foundation of life, is one of the three essential macronutrients, along with carbohydrates and fats. It consists of a chain of essential and nonessential amino acids. The body can synthesize nonessential amino acids itself, while essential amino acids must be obtained from food.

Until recently, scientists knew of 150 types of amino acids, but their list is constantly growing. Proteins have such diverse structures, differing in the number and variations of amino acids, that no two identical molecules are found in our bodies.

The functional role of protein in the body:

• Enzymatic. Most enzymes are proteins responsible for hundreds of chemical reactions in the body. Enzyme imbalances lead to disruptions in various body systems: metabolism, digestion, blood clotting, etc.
• Hormonal. Proteins are components of hormones and act as chemical messengers that improve communication between cells. Some proteins are synthesized by endocrine tissues and are hormones themselves, while others facilitate interactions between various cells in the body, ensuring hormonal balance.
• Transport. It transports important molecules, such as hemoglobin, which carries oxygen to cells. 
• Motor. Actin and myosin are proteins that combine to form actomyosin, a key component of contractile muscles. During intense exercise, muscle fibers are broken down, and protein, the building block, is essential for their repair and growth. Adequate protein in an athlete's diet is essential for building muscle mass and increasing endurance—key factors for achieving high athletic performance.
• Structural. Protein is a component of keratin, collagen, and elastin, which are the structural units of bones, skin, hair, and ligaments, responsible for the ability of tissues to stretch and contract.
• Protective. Antibodies produced by the immune system are protein compounds in blood plasma that protect the body from pathogenic microbes and viruses. Furthermore, special proteins called fibrinogen and thrombin prevent blood loss when capillaries and blood vessels on the skin's surface are damaged.
• Energy. Protein is used as an additional source of energy: the breakdown of 1 g of protein releases 17.6 kJ of energy.
• Regulatory. Regulates the concentration of acids in the blood and other bodily fluids. The protein hemoglobin is responsible for maintaining normal pH levels in the blood.

In addition to those listed, the protein performs a number of other functions: signaling, gene regulation, and storage.

An imbalance between protein intake and protein requirements primarily leads to muscle loss, which has serious consequences for overall health due to weakened immunity, and also affects the condition of the skin, hair, and nails.

What is the essence of a high protein diet? 

The recommended daily protein intake for healthy adults is 0.8 grams of protein per kilogram of body weight per day. With a high-protein diet, this can reach 1.6 to 2 grams of protein per kilogram of body weight per day (or 25-35% of calories from protein). Protein should make up more than half of the daily diet. Fats and carbohydrates are not completely eliminated, but limited as much as possible.

High-protein weight-loss diets have been around since the 1970s and are regularly updated to reflect new products or recipes. They are based on unlimited consumption of meat, eggs, and fish at every meal and range from the method developed by Pierre Dukan to the protein shaker-based diet widely used in sports.

The essence of a protein diet is to drastically reduce the amount of carbohydrates consumed in food, which are the body's primary source of energy. In response, the body begins to search for new "fuel" and finds it in the form of glucose and fat reserves.

Eating plenty of protein helps maintain muscle mass and, with sufficient exercise, even increase it. By reducing fat and carbohydrates in your diet and replacing them with protein, you can feel full and reduce the hunger that typically occurs when following a low-calorie diet.

A protein-rich diet emphasizes dairy products, meat, fish, and eggs. However, it's recommended to vary the sources. Processed meat products and dairy desserts are not recommended for frequent consumption, as they don't contain much protein but are high in sugars and unhealthy fats. Non-protein foods shouldn't be neglected either: vegetables, fruits, and starches should also be included in the daily diet, as the brain requires approximately 30 grams of glucose per day for normal functioning.

The protein diet is a general approach that encompasses various low-carb and high-fat diets. Variations include the no-carb, keto, Atkins, Dukan, Kremlin, Hollywood, and Paleo diets. The basic principle remains the same, but permitted and prohibited foods may vary slightly. To determine the exact permitted frequency of consumption, refer to the recipe for a specific weight loss method (for example, the Dukan diet).

There's also a vegetarian version of the high-protein diet. It's based solely on plant proteins and has a unique feature: it excludes red meat, which is rich in saturated fatty acids. In this version, animal proteins are replaced with grains, oilseeds, tofu, soybeans, or grain-based artificial meat. The vegetarian high-protein diet also includes vegetables and high-quality fats.

A key element of a protein-based diet is adequate hydration: at least 2.5 liters of water per day. This is necessary to ensure proper elimination of waste products produced during protein digestion. Insufficient fluid intake leads to impaired kidney function and the accumulation of toxic substances.

To ensure a protein diet is effective and safe for your health, you need to follow certain rules:

• Reduce your daily calorie intake, as weight loss is only possible with a calorie deficit
• Eat small meals frequently (5-6 times a day), which helps control hunger and reduces the strain on the liver and kidneys.
• Have breakfast immediately after waking up and dinner two to three hours before going to bed.
• Include protein foods in every meal
• Combine animal and plant proteins in your diet, as the latter contains important phytonutrients and antioxidants
• Eliminate sugar
• Eat fruits in the first half of the day
• Prefer boiling, stewing and baking as cooking methods
• Include vegetables in your diet, as they contain fiber, which is necessary for normal digestion.
• Eat lemon because it is rich in citrates, which alkalize the body, which is acidified by a protein diet.
• Take vitamin complexes based on vitamins B, C and D (the latter can promote weight loss)
• Don't forget to drink plenty of water (at least 30 ml per 1 kg of weight)
• Maintain physical activity: brisk walking, fitness or gym classes should be done daily.

What to Eat (List of High Protein Foods) 

Allowed foods for a protein-based diet:

– White meat: veal, rabbit, poultry (chicken, turkey, duck)

– Red meat: beef, horse meat, lamb (maximum twice a week)

– Offal: tongue, liver, kidneys

– Lean fish: cod, hake, haddock, flounder, blue whiting, sole, canned tuna

– Shellfish: oysters, mussels, scallops, squid, shrimp

– Seaweed: sea lettuce, wakame, nori sushi, spirulina. Eggs (chicken and quail, raw, boiled, omelet)

– Dairy products: low-fat cottage cheese and yogurt, aged cheese, low-fat milk (cow, goat, sheep, mare), butter (with limitations)

– Legumes: beans, chickpeas, lentils

– Cereals (whole grain): brown rice, buckwheat, bran, oats

– Seeds: flax, sesame, sunflower, poppy, pumpkin

– Nuts: almonds, walnuts, Brazil nuts, pecans, cashews, pine nuts, hazelnuts, pistachios, peanuts

– Mushrooms: porcini, shiitake, chanterelles

– Savory vegetables: artichokes, asparagus, beans, zucchini, eggplant, avocado, celery, cabbage (cauliflower, broccoli, Brussels sprouts, Romanesco, red), cucumbers, spinach, fennel, green beans, turnips, onions, sorrel, leeks, peppers, radishes, tomatoes, salads

– Herbs: dill, basil, green onions, coriander, tarragon, mint, oregano, parsley, rosemary, sage, thyme.

– Fruits: citrus fruits, green apples, unsweetened pears, currants, kiwi

– Drinks: soy, almond, oat, chestnut, coconut, rice, hemp or sesame milk, as well as tea, coffee and herbal infusions

– Seasonings: apple cider vinegar, brewer's yeast, spices, mustard, salt (limited)

– Sprouted seeds and cereals

– Omega 3 fats: walnuts, hemp, rapeseed, flax, camelina, wheat germ

– Omega 6 fats: olive, sunflower, safflower, sesame Concentrated vegetable proteins: seitan, tofu, tempeh, humus

Important! If you have an allergy or food intolerance to certain foods (such as lactose), you should eliminate it from your diet and replace it with other proteins.

If your body isn't getting enough protein from food, you can compensate with protein supplements. These easily digestible protein foods provide the necessary amount of protein in the simplest and most convenient way.

Popular protein products available at Vansiton online store:

1. VANSITON FOR COCKTAILS with strawberry flavor
2. Vanciton Ultra-Pro Banana
3. VANSITON EXTRA Vanilla
4. Optimum Nutrition 100% Whey Gold Standard Double Rich Chocolate Whey Protein
   
5. Optimum Nutrition Whey Protein 100% WHEY Gold Standard 2.27 kg Chocolate Malt
6. Protein Bar Marzipan + Almonds from TM Nutrend protein bar

What you can't eat 

Prohibited foods on a high protein diet:

– Bread, pasta, and baked goods. A small slice of whole grain bread is allowed no more than 1-2 times a week.

– Flour and confectionery products containing sugar: candies, cookies, gingerbread, pastries, cakes, sweet rolls, desserts, etc.

- Honey

– Meat: fatty pork, smoked, salted, dried meat and sausages

– Breakfast cereals: cornflakes, puffed rice, coconut chips

– Processed and industrial foods: fast foods, canned goods, pizza, mayonnaise, ketchup, as they contain a lot of starch and sugar

– Food additives: sweeteners, preservatives, flavor enhancers, synthetic flavors.

– Fats: lard, margarine, industrial sauces, fried foods, refined oils, peanut and coconut oil

– Sweet vegetables and fruits: carrots, beets, pumpkin, mango, banana, grapes, melon, figs, dates, apricots, peaches, etc.

– Starchy vegetables: potatoes, corn

- Spices

– Alcohol: wine, beer, spirits

– Sweet soft drinks (soda, fruit drinks, compote, store-bought juices)

Animal protein versus plant protein 

Not all proteins are created equal. Their nutritional value depends on the composition of essential amino acids and their bioavailability. Egg white, with a chemical index of 100, is the standard. All animal proteins also have an index close to 100.

The glycemic index of plant proteins found in grains (barley, rice, oats), as well as beans and soybeans, is around 80. They don't contain all the essential amino acids, so they need to be combined to increase their glycemic index. Furthermore, they contain starch, a complex carbohydrate that eventually converts to glucose, even though these foods have a moderate glycemic index.

Therefore, if you want to reduce your meat intake, especially red meat, you can switch to pure plant proteins, such as soy, found in tofu, tempeh, or miso, paired with fish or poultry. When consuming only plant proteins (if you're vegetarian), it's crucial to engage in daily physical activity to burn as much energy as possible.

Sample menu for a week 

We offer one of the protein diet menu options for 7 days

Monday

1st breakfast : 2 eggs, 1 slice of chicken breast, coffee

2nd breakfast : low-fat yogurt

Lunch : pumpkin soup, veal cutlet with stewed zucchini

Afternoon snack: a handful of almonds

Dinner : Baked cod, vegetable salad with feta

Tuesday

1st breakfast : 150 g smoothie made from protein powder (whey, pea, egg), unsweetened tea

2nd breakfast : fruit salad with apples and citrus fruits

Lunch : vegetable soup, 150g boiled chicken breast with stewed zucchini, a slice of whole grain bread

Afternoon snack : 100 g Greek yogurt

Dinner : 200g baked fish and vegetable salad with tofu

Wednesday

1st breakfast : buckwheat porridge with milk, herbal tea

2nd breakfast: 1 orange

Lunch : Fish soup without potatoes, 200 g of boiled turkey with brown rice

Afternoon snack : 50 g tofu cheese

Dinner : 150 g of boiled fish with lentils and steamed vegetables

Thursday

1st breakfast: quail egg omelette, sandwich with hard cheese, coffee

2nd breakfast : 1 glass of kefir or fermented baked milk

Lunch : chicken breast broth, veal or chicken steak, 100 g asparagus beans

Afternoon snack : 1 glass of protein drink

Dinner: 150 g of baked fish with stewed cabbage

Friday

1st breakfast: cottage cheese casserole, green tea

2nd breakfast: a handful of mixed nuts

Lunch: 150 g beef liver, vegetable ratatouille (onion, eggplant, zucchini, cauliflower, bell pepper, tomato)

Afternoon snack: 1 glass of kefir

Dinner: 200 g boiled mussels (or other seafood) with brown rice

Saturday

Breakfast 1: Flaxseed porridge, whole grain bread sandwich with ricotta and blueberries, coffee

2nd breakfast : 1 glass of almond milk

Lunch: vegetable soup, 200 g of stewed rabbit with boiled broccoli

Afternoon snack: protein bar

Dinner: 150 g of hake stewed with vegetables and a side dish of green buckwheat

Sunday

1st breakfast: a piece of boiled chicken breast with lettuce leaves, 1 glass of soy milk

2nd breakfast: baked apple

Lunch: porcini mushroom soup, lazy vareniki with sour cream

Afternoon snack: a handful of seeds and nuts

Dinner: 200g tuna salad with avocado and green vegetables

The portions listed correspond to the needs of an average-sized person with normal physical activity (up to 30 minutes per day). Therefore, for women, the recommended protein intake is 30 to 40 grams per meal, and for men, 35 to 50 grams, across three meals a day.

Athletes or those engaged in heavy physical labor can increase their daily calorie intake. As part of a protein diet, diuretic herbal teas made from dandelion, birch, ash, meadowsweet, nettle, horsetail, burdock, borage, or elderberry can be consumed to promote the elimination of uric acid.

Benefits of a protein diet 

Nearly 40 controlled studies conducted in the United States have shown that increased protein intake reduces systolic and diastolic blood pressure by an average of 1.76 mmHg and 1.15 mmHg, respectively. High-protein foods boost metabolism and increase calorie burn, as digesting and absorbing protein requires a lot of energy. Furthermore, a healthy protein diet promotes better blood sugar control and increased insulin sensitivity.

The positive aspects of a protein diet include:

• Rapid weight loss without losing muscle mass
• Lack of hunger and cravings for food
• Easy to follow at home
• A large list of permitted foods for creating a varied diet
• The ability to create a simple menu with individual food preferences
• Lose weight by burning fat without losing muscle mass
• Suitable for athletes and older adults who lose muscle mass with other calorie-reducing diets
• Improving metabolism by activating metabolic processes
• Strengthening bones, improving the condition of skin, hair and nails
• Acceleration of skin surface regeneration processes

Studies have shown the high effectiveness of a protein diet in treating obesity, resulting in sustained weight loss. This helps prevent many associated conditions (digestive and metabolic disorders, hormonal imbalances, psychological disorders, etc.).

Disadvantages of a protein diet 

Unfortunately, excessive protein consumption can have negative health consequences. Experts warn against the misuse of all known pure protein diets.

Why is a protein diet dangerous?

• Increased levels of bad cholesterol in the blood, acidification of the blood
• Deterioration of the renal and cardiovascular systems
• Hormonal imbalances (in women), menstrual irregularities, weakened ovarian function
• Increased blood clotting and risk of thrombosis; rapid, but often short-term, weight loss; unpleasant side effects due to nutrient deficiencies and transit disturbances; risk of the yo-yo effect (weight gain due to fat deposition after stopping the diet)
• Exacerbation of gastritis and enterocolitis

Another disadvantage of a protein diet is its high cost, as meat and fish are expensive.

Duration of the protein diet and how to stop it 

The duration of a high-protein diet varies greatly and depends on the chosen method. Nutritionists note that while it's very effective for weight loss, it's not suitable for weight maintenance.

The minimum duration of a weight loss diet is one week. During this time, you can lose 4 to 5 kg of fat. A strict protein diet lasting 10 days to 2 weeks allows you to lose 8 to 15 kg. The maximum allowable period for this diet, if well-tolerated and in the absence of chronic diseases, is one month.

If your health deteriorates significantly, you should stop the protein diet immediately and consult a doctor!

It is important not only to stick to a diet correctly, but also to exit it without harming the body.

To avoid gaining back the lost kilograms and to avoid losing your health, you must follow these rules:

1. The period of exit from the diet should be twice as long as the diet itself.
2. Try to maintain the same volume and number of servings
3. Introduce prohibited foods into your diet gradually: first fruits and vegetables (excluding potatoes), then fatty meats, cereals, and finally, bakery products, pasta, potatoes, sweets, and alcohol (no earlier than 5 days after completely switching to a normal diet).

Common mistakes

The most common mistakes when following a protein diet include:

• The choice of sausages, hot dogs, smoked meats and other industrially produced meat products as the main source of protein.
• Using exclusively animal protein in the diet without vegetable protein
• Giving up fruit
• Drinking small amounts of liquid
• Uncontrolled consumption of large amounts of protein
• A sudden refusal of carbohydrates, which is stressful for the body
• Complete exclusion of high-calorie foods, which is fraught with a lack of beneficial nutrients that they contain

Be careful when using sports nutrition: a high-protein diet usually requires the addition of vitamins, minerals, and essential fatty acids to avoid deficiencies.

An important rule of the protein diet is gradual change. It's a good idea to begin the transition to a new menu by compiling a list of prohibited foods that you should avoid purchasing.

About two weeks before starting the diet, you should begin limiting your intake of sweet and starchy foods, reducing your overall carbohydrate intake. During this same period, you should gradually eliminate some spices from your diet and reduce your salt intake. About one to two days before the diet, you can begin eliminating other undesirable foods from your diet. Meditation, yoga, breathing exercises, nature walks, and creative pursuits can help reduce stress.

Possible risks and contraindications to the diet 

Research was conducted at the University of Granada in Spain to examine the adverse effects of high-protein diets on kidney health. Two groups of rats were used in the experiment. One group was fed a normal-protein diet for 12 weeks, while the other group was fed a high-protein diet for 12 weeks. Results showed a 10% weight loss in the rats after 12 weeks on the high-protein diet. However, their urinary citrate levels, which inhibit calcium crystal formation, were 88% lower, and their urine pH became 15% more acidic.

The body increases urinary calcium secretion to compensate for the acidity caused by excessive protein consumption. Low citrate levels, acidic urine pH, and high urinary calcium levels are risk factors for kidney stones.

Experts point out that lean cuts of red meat tend to raise blood cholesterol levels due to their saturated fatty acids. Therefore, in the long term, a pure protein diet poses a risk to the cardiovascular system.

Possible side effects that may occur with a high protein diet include:

• bad breath and flatulence due to prolonged digestion of protein foods and their retention in the intestines
• fatigue, headaches
• constipation on a protein diet
• mild cognitive impairment due to carbohydrate deficiency
• swelling.

A protein diet is not recommended:

• Pregnant women and during lactation
• Children and adolescents, as they need carbohydrates
• For patients with oncological diseases
• Patients with chronic kidney, liver and gastrointestinal disorders
• For type 1 diabetes, metabolic disorders, cardiovascular diseases.

Considering that excessive consumption of fish and meat can negatively impact kidney health, a vegetarian, high-protein diet may be a more appealing option. In any case, nutritionists advise against following a strict high-protein diet for long periods of time.

Experience shows that losing weight with protein is easy, but the risk of regaining the weight and the yo-yo effect remains high. After a long diet, the weight is almost guaranteed to return, weakening your body. Maintaining protein-based weight loss can be achieved by switching to a varied and balanced diet, such as the Mediterranean diet, combined with regular physical activity.

Scientific sources: