Nutrition and Training: The Complete Guide

Training is only part of the equation. Without proper nutrition, even the best program will not deliver optimal results. For a summary of the fundamentals, also check out our article on the basics of nutrition for training. This guide covers the essential nutritional principles to support your strength training progression, whether your goal is muscle gain, fat loss or body recomposition.

Understanding caloric needs

Your body expends energy constantly. This total expenditure, called TDEE (Total Daily Energy Expenditure), depends on several factors: your basal metabolic rate, your physical activity level, the thermic effect of food and your non-exercise activity (NEAT).

Caloric surplus: for building muscle

To build muscle, your body needs more energy than it expends. A surplus of 300 to 500 calories per day is generally sufficient to maximize muscle protein synthesis without accumulating too much fat.

An excessively large surplus (700+ calories) will not make you gain muscle faster, but will significantly increase fat storage. The body has a limited daily capacity for protein synthesis, and caloric excess beyond that limit is stored as adipose tissue.

Caloric deficit: for losing fat

To lose fat while preserving muscle, aim for a moderate deficit of 300 to 500 calories per day. An overly aggressive deficit increases the risk of muscle loss, decreases training performance and can disrupt your hormonal system.

During a deficit, keep your protein intake high (2.0 to 2.4 g/kg) and continue training with heavy loads. These two factors are the most important for preserving muscle mass during caloric restriction.

Calculating your needs

A simple method to estimate your TDEE:

1. Calculate your basal metabolic rate: bodyweight (kg) x 22 for men, bodyweight (kg) x 20 for women.
2. Multiply by an activity factor: 1.4 (sedentary), 1.6 (moderately active), 1.8 (very active).
3. Adjust based on your goal: +400 kcal for muscle gain, -400 kcal for fat loss.

These formulas are only estimates. Weigh yourself every morning on an empty stomach and calculate the weekly average. If your weight does not change after 2 weeks, adjust by 200 calories in the desired direction.

Macro summary table by goal

For an 80 kg man training 4 times per week, here are the recommended ranges:

Notes: During a cut, protein is increased to compensate for the reduced anti-catabolic effect of the caloric surplus. For recomposition, the goal is to stay very close to maintenance, which requires high protein intake and well-periodized training to simultaneously stimulate fat loss and muscle gain.

Macronutrients in detail

Protein: the building block

Protein provides the amino acids necessary for repairing and building muscle fibers. The recommended intake for a strength training practitioner is 1.6 to 2.2 g per kg of bodyweight per day.

The best protein sources are:

• Lean meats: chicken, turkey, lean beef (20-25 g of protein per 100 g)
• Fish: salmon, tuna, cod (18-25 g per 100 g)
• Eggs: 6 g of protein per egg, complete amino acid profile
• Dairy: cottage cheese, Greek yogurt, skyr (8-12 g per 100 g)
• Legumes: lentils, chickpeas, beans (7-9 g per 100 g cooked)

Spread your protein across 3 to 5 meals per day, with at least 25 to 40 g per meal to maximize muscle protein synthesis. AIVancePro’s AI coach automatically calculates your protein needs based on your weight, goal and training volume.

Protein sources: density and value

Not all protein sources are created equal. The DIAAS (Digestible Indispensable Amino Acid Score) measures a protein’s quality based on its digestibility and essential amino acid profile. A score above 100 indicates a very high quality protein.

How to read this table: Whey offers the best cost-to-protein ratio in terms of pure protein, but should not replace whole foods. Lentils are economical but their lower DIAAS score means they need to be combined with other sources (grains, for example) to achieve a complete amino acid profile.

Carbohydrates: the fuel for effort

Carbohydrates are the primary energy source for intense efforts like strength training. They replenish muscle glycogen stores, which allows you to maintain high performance during training.

Recommended intake varies by goal:

• Muscle gain: 4 to 7 g/kg/day
• Maintenance: 3 to 5 g/kg/day
• Fat loss: 2 to 4 g/kg/day (reduced progressively)

Prioritize complex sources: rice, whole grain pasta, sweet potatoes, oats, quinoa. These foods provide stable energy and are rich in fiber and micronutrients.

Fats: essential but often neglected

Fats play a crucial role in hormone production (testosterone, growth hormones), fat-soluble vitamin absorption and cellular health. Never go below 0.8 g/kg/day.

An intake of 0.8 to 1.2 g/kg/day is ideal. Recommended sources:

• Olive oil: monounsaturated fatty acids, anti-inflammatory
• Nuts and almonds: healthy fats, fiber, minerals
• Avocado: rich in potassium and monounsaturated fats
• Fatty fish: salmon, sardines (omega-3 EPA and DHA)
• Egg yolks: cholesterol necessary for hormonal synthesis

Meal timing

Nutrient timing is less important than total daily macronutrient intake. However, a few principles can optimize your results:

Around training

• Before (1-2h): a meal containing carbs and protein to ensure good energy levels. Example: 80 g of oats + 1 banana + 30 g whey.
• After (within 2h): a protein and carb-rich meal to kickstart recovery. Example: 150 g of chicken + 200 g of rice + vegetables.

The 30-minute anabolic window after training is a myth. As long as you consume a protein-rich meal within 2 to 3 hours after your session, you optimize recovery. For more on this topic, our guide on recovery and injury prevention covers all aspects of rest and regeneration.

Before bed

A slow-digesting protein source (casein, cottage cheese) before sleep can maintain protein synthesis during the night. 200 g of cottage cheese provides approximately 16 g of protein, primarily in the form of casein.

Hydration

Water makes up approximately 75% of muscle tissue. Even mild dehydration (2% of bodyweight) can reduce your performance by 10 to 20%. Aim for 35 to 45 ml of water per kg of bodyweight per day, plus an additional 500 ml to 1 liter during training.

Indicators of good hydration: clear to pale yellow urine throughout the day. If it is dark, you are not drinking enough.

Vegetarian diet and strength training

It is entirely possible to reach the recommended 1.6 to 2.2 g/kg of protein per day without meat or fish. It does, however, require more careful planning.

The leucine challenge

Leucine is the most important amino acid for triggering muscle protein synthesis. The optimal threshold is approximately 2.5 to 3 g of leucine per meal. Plant-based sources generally contain less leucine than animal sources: you need about 40 g of plant protein per meal to reach this threshold, compared to 25 to 30 g of animal protein.

Combinations for a complete profile

Plant proteins taken individually often have a limiting amino acid. The solution is to combine sources throughout the day (not necessarily in the same meal):

• Grains + legumes: rice + lentils, bread + hummus, pasta + kidney beans
• Legumes + seeds: chickpea salad + sunflower seeds
• Soy + grains: tofu + rice, edamame + quinoa

Best vegetarian sources

• Eggs: complete profile, DIAAS 116 (the best vegetarian option)
• Dairy: cottage cheese, whey, Greek yogurt
• Soy and derivatives: tofu (12 g/100 g), tempeh (19 g/100 g), edamame (11 g/100 g)
• Seitan: 25 g protein/100 g (note: low in lysine, combine with legumes)
• Legumes: lentils, chickpeas, black beans
• Plant-based protein powders: pea + rice blend for a complete profile

For vegan practitioners (no eggs or dairy), creatine and vitamin B12 supplementation is essential. A blend of plant-based protein powders (pea + rice) is a practical tool to round out intake.

Alcohol and strength training

Alcohol is often underestimated in its impact on strength training progression. Here is what the science tells us.

Impact on protein synthesis

The study by Parr et al. (2014, PLOS ONE) demonstrated that alcohol consumption after training reduces muscle protein synthesis by approximately 24%, even when protein intake is adequate. In practical terms, your training session produces fewer results if you consume alcohol in the hours that follow.

Hormonal impact

Alcohol disrupts the hormonal environment in several ways:

• Testosterone: heavy consumption (>5 drinks) can reduce testosterone levels by 20 to 25% for 12 to 24 hours.
• Cortisol: alcohol increases cortisol secretion, a catabolic hormone that promotes muscle breakdown.
• Growth hormone: nocturnal GH secretion is reduced by up to 70% after alcohol consumption.

Impact on sleep and recovery

Alcohol reduces the duration of deep sleep and REM sleep, the two phases most important for muscle recovery and training adaptation consolidation. Even 2 drinks in the evening are enough to impair sleep quality. Our guide on recovery and injury prevention details the importance of sleep for progression.

Practical recommendations

Total abstinence is not necessary, but a few rules help limit the impact:

• Avoid alcohol on training days, especially within 6 hours after your session.
• Limit yourself to 1-2 drinks maximum during social occasions.
• Stay hydrated: alternate one glass of water for each alcoholic drink.
• Eat enough protein on days when you consume alcohol — this partially mitigates the anti-anabolic effect.
• Don’t forget the calories: alcohol provides 7 kcal/g, and sugary mixers easily add 200-300 kcal per drink.

Supplements: useful vs marketing

Science-backed supplements

• Creatine monohydrate: the most studied and most effective supplement. Improves strength, power and muscle volume. Dose: 3 to 5 g per day, every day. No loading phase needed.
• Whey protein: not a magic supplement, simply a practical protein source when diet falls short. 25 to 40 g per serving.
• Caffeine: improves performance, focus and reduces perceived effort. 3 to 6 mg/kg, 30 to 60 minutes before training.
• Vitamin D: essential if you have limited sun exposure (the majority of the population in winter). 2,000 to 4,000 IU per day.

Useless or overhyped supplements

• BCAAs: unnecessary if your protein intake is sufficient. Whey already contains all the BCAAs you need.
• Fat burners: marginally effective at best, often just overpriced caffeine.
• Testosterone boosters: no over-the-counter supplement significantly increases testosterone in a healthy individual.
• Glutamine: no demonstrated benefit for muscle recovery in healthy individuals.

Meal examples

Muscle gain breakfast (~700 kcal)

• 100 g oats with milk
• 1 banana
• 3 whole scrambled eggs
• 10 g peanut butter

Balanced lunch (~600 kcal)

• 150 g grilled chicken
• 200 g basmati rice
• Green vegetables (broccoli, green beans)
• 1 tablespoon olive oil

Post-workout snack (~400 kcal)

• 30 g whey in 300 ml water
• 1 banana
• 30 g mixed nuts

Fat loss dinner (~450 kcal)

• 200 g salmon
• 150 g sweet potato
• Green salad with avocado
• Lemon vinaigrette

Adjust quantities to your individual caloric needs. The important thing is to hit your daily macronutrient targets, not to achieve perfection at every meal. To pair these nutritional principles with an adapted training plan, discover how to create an effective training program.

Tracking and adjustments

Nutrition is not an exact science applied to the individual body. Calculation formulas are only starting points — the real work lies in regular tracking and progressive adjustments.

How to weigh yourself correctly

Weigh yourself every morning, on an empty stomach, after using the bathroom. Record the number without placing too much importance on it day to day: weight naturally fluctuates by 0.5 to 2 kg from one day to the next depending on hydration, digestion and the previous day’s carb intake (1 g of stored glycogen holds approximately 3 g of water).

Calculate your weekly average and compare averages from week to week. That is the only trend that matters.

When to adjust calories

Do not change anything before you have 2 to 3 weeks of stable data on the same caloric intake. The body needs time to adapt and initial fluctuations (especially at the start of a diet) do not always reflect reality.

Signs that an adjustment is needed:

• Muscle gain: if you are not gaining 0.2 to 0.5 kg per week on average, increase calories.
• Fat loss: if you are not losing 0.3 to 0.7 kg per week on average, reduce calories.
• Maintenance: if your weekly average drifts by more than 0.5 kg over 3 weeks, adjust.

How to adjust

Proceed in increments of +/-200 kcal (approximately 50 g of carbs, or 25 g of carbs + 10 g of fats). Avoid sudden changes of 500+ kcal that disrupt adherence and make analysis harder.

After each adjustment, wait another 2 to 3 weeks before re-evaluating. Patience is the most underrated skill in sports nutrition. AIVancePro makes this tracking easier by correlating your weight, gym performance and training volume to indicate when a nutritional adjustment is relevant. To structure your progression phases over time, see our guide on training periodization.

Tracking tools

You do not need to weigh every food indefinitely. Two approaches work:

• Learning phase (4-8 weeks): weigh and track everything to calibrate your eye. Use a calorie tracking app.
• Autonomous phase: once you know portion sizes, you can estimate visually. Return to precise tracking if results stall.

Want to optimize your nutrition alongside your training? AIVancePro automatically adapts your nutritional recommendations based on your program and goals, so every meal supports your progression. Download the app for free and get started today.

FAQ

Do I need to count calories?

Not necessarily for life, but it is a powerful tool for understanding what you actually eat. Most people underestimate their caloric intake by 20 to 40%. Count your calories for 4 to 8 weeks to calibrate your perception of portions, then switch to visual estimation. If you plateau, return to precise tracking for a few weeks to identify the problem.

How many meals per day?

The number of meals has very little impact on body composition as long as total macronutrient intake is met. However, to optimize protein synthesis, spreading protein across 3 to 5 meals of 25 to 40 g is preferable to concentrating everything in 1 or 2 meals. In practice, 3 meals + 1 or 2 snacks works well for most lifters. Intermittent fasting is compatible with strength training, but makes optimal protein distribution more difficult.

Whey or casein?

Both have their place. Whey is digested quickly (amino acid peak in 30-60 minutes), making it a good choice around training or when you need a quick intake. Casein digests slowly (gradual release over 6-8 hours), ideal before bed to maintain protein synthesis overnight. If you can only choose one, go with whey — it is more versatile. Cottage cheese (rich in casein) can easily replace a casein shake before bed.

Is meal prep essential?

No, but it is a considerable advantage. Preparing meals in advance (on Sunday for the week, for example) reduces mental load, improves adherence to the nutritional plan and decreases the temptation to order an unsuitable meal. Start simple: prepare 2 to 3 protein and carb sources in large batches, and assemble your meals daily. You do not need 7 identical containers to be organized.