There are bodybuilding champions, there are movie stars, and there are cultural icons. Then there’s Arnold Schwarzenegger – a man who managed to excel at all three.

At his competitive peak, Arnold built the broad shoulders, mountainous chest and cartoonishly small waist that helped define bodybuilding’s golden era. His physique remains one of the most recognisable – and arguably most influential – bodies ever built.

So, in his heyday, what did the GOAT believe you should eat to pack on serious muscle?

In The New Encyclopedia of Modern Bodybuilding, Schwarzenegger laid out both his fundamental rules for gaining size and a three-level meal plan designed to keep the scales moving upwards. Some of the advice is unmistakably old-school, and the quantities become increasingly eye-watering, but the underlying approach is more measured than the stereotypical ‘see-food diet’ often associated with bulking.

Arnold’s prescription was simple: train hard, eat enough protein, gradually increase your calories and avoid turning a muscle-building phase into an excuse to get unnecessarily fat.

Here’s how he broke it down.

Arnold’s recommendations were aimed primarily at young, naturally skinny bodybuilders who began training in what he called a ‘Hey, skinny, your ribs are showing’ state.

For these hard-gainers, he identified four priorities.

First, you need to create a reason for your body to grow. Arnold recommended ‘heavy, intense, consistent bodybuilding training’ to stimulate muscular development. Calories and protein may supply the raw materials, but without progressive resistance training there’s no meaningful demand for your body to add new tissue.

Second, you need sufficient protein to meet what Schwarzenegger described as the increased demand for amino acids created by training. His sample menus are extremely protein-heavy by modern standards, but the fundamental message remains sound: you cannot expect to maximise muscle growth while treating protein as an afterthought.

Third, Arnold advised increasing your overall caloric intake enough to support hard exercise and growth – but ‘not so much as to create an unwanted gain in body fat’.

That distinction is noteworthy. This wasn’t an indiscriminate dirty bulk. Arnold explicitly warned that being naturally lean ‘doesn’t mean that eating a lot of junk food and empty calories is good for you’.

Instead, his guidance was to ‘train hard and eat more’, while trying to eat clean and choosing nutritious meals. After all, he reasoned, you cannot build muscle if you lack the energy and nutrients required to support it.

Finally, Arnold recommended keeping aerobic exercise to what he called a ‘healthy minimum’ during a dedicated mass-building phase – no more than 30 minutes a day, four or five days a week.

Which, to be fair, is still a very healthy and aspirational amount.

He also cautioned against performing cardiovascular training immediately before lifting. Although some trainees treat aerobics as a warm-up, Arnold argued that it can fatigue the body and make it harder to train with the intensity you’re capable of producing.

That doesn’t mean cardio is inherently bad for muscle growth. But if size and strength are the priorities, your hardest lifting should receive the best of your energy and attention.

Rather than immediately doubling your food intake, Arnold proposed a gradual, three-stage system.

His reasoning was practical: ‘Stuffing a lot of calories into your body at one time is not a good idea.’ The digestive system may not be prepared to handle a sudden and dramatic increase in food volume.

Instead, he recommended beginning with Level I and remaining there for as long as bodyweight continued to rise. Once weight gain stopped – or if no increase occurred after three weeks – you moved to Level II.

The same rule applied again. Continue eating at Level II while the scales are moving. When progress stalls, graduate to Level III.

This is essentially an old-school version of progressive overload for your diet. You begin with the smallest effective increase, monitor the result and add more food only when necessary.

Arnold also recommended spreading calories across more than three meals per day. Four meals could make a higher intake easier to tolerate, while protein drinks offered an inexpensive way to add calories and amino acids without forcing down another huge plate of food.

He recalled using this strategy himself at 15 years old, when he was desperate to gain weight. Protein drinks, he said, not only helped satisfy his need for additional calories and amino acids, but also cost less than many other high-protein foods.

Arnold’s plan is built around three substantial meals, with the option to add protein drinks between them. As the levels rise, so do the portions, calories and listed protein totals.

It’s worth noting that the figures printed in the book appear extremely high and will vary significantly depending on the exact cuts of meat, dairy products and portion sizes used. Treat this as a historical bodybuilding template rather than a rigid prescription.

Level 1

Arnold advised starting here and remaining on this intake until bodyweight stopped increasing.

Breakfast

Two eggs, prepared however you prefer, alongside a quarter-pound serving of meat, fish or poultry. Add eight ounces of whole milk and one slice of whole-grain toast with butter.

Arnold lists the meal at approximately 52g of protein

Lunch

A quarter-pound of meat, fish, poultry or cheese, served with one or two slices of whole-grain bread and eight ounces of whole milk or fresh juice.

Approximate protein: 43g

Dinner

Half a pound of meat, fish or poultry with a baked potato topped with butter or sour cream, a large raw salad and eight ounces of whole milk.

Approximate protein: 48g

Across the three meals, Arnold’s stated total comes to roughly 143g of protein, before adding any supplemental drinks.

Level 2

If Level I fails to produce weight gain after three weeks – or eventually stops working – Arnold recommends increasing the portions.

Breakfast

Three eggs, a quarter-pound of meat, fish, poultry or cheese, eight ounces of whole milk and one or two slices of whole-grain toast with butter.

Approximate protein: 61g

Lunch

Half a pound of meat, fish, poultry or cheese – or a combination – with two slices of whole-grain bread, butter or mayonnaise, eight ounces of whole milk and a piece of fresh fruit.

Approximate protein: 71g

Dinner

Half a pound of meat, fish, poultry or cheese, accompanied by a baked or boiled white or sweet potato and a large raw salad.

Approximate protein: 59g

That produces a listed daily intake of around 191g of protein.

Level 3

Level III is where the plan becomes a genuine golden-era bodybuilding bulk.

Breakfast

Four eggs, eight ounces of whole milk, one or two slices of whole-grain bread with butter and a piece of fresh fruit.

Arnold suggests that oatmeal, bran cereal or another cooked cereal can replace the bread and fruit, ideally sweetened only with fructose. Half-and-half or cream can be used when even more calories are required.

Approximate protein: 72g

Lunch

Half a pound of meat, fish, poultry or cheese, one or two slices of whole-grain bread with butter or mayonnaise, eight to 16 ounces of whole milk and a piece of fruit, with optional cottage cheese.

Approximate protein: 74g

Dinner

Between half a pound and a full pound of meat, fish, poultry or cheese, plus potato or beans, lightly steamed vegetables, a large raw salad, fresh fruit and eight ounces of whole milk.

Approximate protein: 112g

Taken literally, Arnold’s figures push Level III towards an enormous 258g of protein per day.

Arnold’s exact menu won’t suit everyone. The food choices are repetitive, the dairy intake is substantial and Level III contains enough meat to make many modern nutritionists wince.

But beneath the whole milk, butter and half-pound servings is a sensible system.

One that – to be honest – still stands up today.

Train with enough intensity to create a stimulus. Eat sufficient protein. Raise calories gradually rather than force-feeding yourself from day one. Monitor bodyweight, and only increase your intake when progress stalls. Most importantly, don’t confuse building muscle with eating everything in sight.

Arnold may have built one of the greatest physiques of all time, but his nutritional philosophy wasn’t complicated: earn your growth in the gym, support it at the dinner table, and keep adding food only for as long as you need it.

With almost 18 years in the health and fitness space as a personal trainer, nutritionist, breath coach and writer, Andrew has spent nearly half of his life exploring how to help people improve their bodies and minds.    

As our fitness editor he prides himself on keeping Men’s Health at the forefront of reliable, relatable and credible fitness information, whether that’s through writing and testing thousands of workouts each year, taking deep dives into the science behind muscle building and fat loss or exploring the psychology of performance and recovery.   

Whilst constantly updating his knowledge base with seminars and courses, Andrew is a lover of the practical as much as the theory and regularly puts his training to the test tackling everything from Crossfit and strongman competitions, to ultra marathons, to multiple 24 hour workout stints and (extremely unofficial) world record attempts.   

 You can find Andrew on Instagram at @theandrew.tracey, or simply hold up a sign for ‘free pizza’ and wait for him to appear.