What is it?

The old-school bodybuilding diet (OSBD) has been around since the 1970’s, and was the first form of dieting to be extremely popular, especially among recreational fitness fanatics and bodybuilders. Mainstream bodybuilders such as Arnold Schwarzenegger and Franco Columbu discussed their dieting methods in interviews or films such as Pumping Iron, and unsurprisingly the public imitated the routines of those with superior physiques.

As nutritional science was far more limited back then, dieting techniques were largely based off subjective improvements when dietary alterations were made.

The mentality of dieting to lose body fat was extremely simple:

  • Stick solely to a limited range of whole, unprocessed foods.
  • An animal-based protein source with every meal to retain muscle (one serving of beef/chicken/fish).
  • A small quantity of ‘clean’ carbohydrates with each meal, but largely avoided post-training or near sleep (sweet potato/brown rice). This was said to be the key to losing body fat.
  • A portion of green vegetables with each meal (green beans/broccoli)
  • The occasional egg or glass of milk added to meals.
  • Avoid the use of sodium-containing products (salt).
  • ~6-8 small meals per day, every few hours, to ‘increase the metabolism’.
  • One cheat day per week, where all foods in any quantity are allowed. This is said to ‘shock the body and rev up the metabolism’.

Despite the age of the diet, and with current research disproving many of the dated scientific theories people used to have about nutrition, the OSBD is still widely used and trusted by many to shed the pounds.

The Benefits

  • The diet works, for most 

Like any diet that limits consumption of high caloric foods and focuses on whole foods in small quantities, you will notice initial weight loss due to indirectly producing an energy deficit.

Although the diet was claimed to work by eating ‘fat-burning’ foods, and increasing the metabolic rate by increasing meal frequency, this has been largely debunked. A study found 3 meals per day produced the same fat loss results and metabolic alterations in comparison to 14 meals per day, even when caloric intake was identical [1]. Further to this, feelings of hunger and satiation were improved in the lower meal frequency group with larger volumes of food per meal.

A similar study also found increasing meal frequency from 3 to 6 per day has no significant effect on 24-hour fat oxidation, but may increase hunger and the desire to eat [2]. Theories behind certain ‘fat-burning’ foods are also unscientific and without supporting evidence. In fact, as foods contain energy they actually do the complete opposite and act as weight loss inhibitors. However, high protein foods (the basis of the OSBD) do have higher thermic effects (the energy required for digestion, absorption, and disposal of a nutrient) and therefore play a significant role in controlling net energy balance and favouring fat loss.

  • Structure

This is personal preference, but some people like to be prepared and know exactly what they are doing and when as opposed to implementing flexibility such as in IIFYM. For many, structure can come with perseverance. It requires less thought, and less time to contemplate over food options and quantities.

You either follow the routine or you don’t. The OSBD gives you a strict yet simple regimen so you always know the plan of attack for the proceeding day, the day after that, and so on. Reducing the amount of external or internal factors within the diet and controlling potential variability day to day with things such as sodium, or fat/carb ratios, can also be beneficial at avoiding fluctuations in water weight and help with weight tracking and management.

  • High protein intake

When dieting and in a state of negative energy balance, protein intake becomes crucial for the maintenance of lean tissue stores. A high protein intake can help retain a balanced nitrogen state, dampen the effect of a catabolic environment in an energy deficit, and keep a high rate of muscle protein synthesis.

After all, dieting should be to reduce fat tissue rather than just total weight. The ‘protein requirement continuum’ is a good measure to assess individual protein needs in different circumstances. The lower intakes of the spectrum are 0.8-1.2g/kg bodyweight, for those in hypercaloric states (energy surplus), based on studies by Wilson [3] and the ADA [4]. The higher intakes of the spectrum are 1.4-3.1g/kg, focusing on those in an energy deficit who participate in resistance training and are looking to achieve low levels of body fat [5]. The OSBD has ~30-40 grams of protein per meal, with a daily total of ~180-240 grams. This is clearly enough to fit within evidence-based protein recommendations when dieting for 99.9% of individuals.


The Cons

  • Micronutrient deficiencies

The problem with severely limiting the amount of different foods you can eat within a diet is that you leave yourself vulnerable to lacking one or many different micronutrients. Let’s see a practical example:

6-8 generic small meals in the OSBD roughly totals 700 grams (raw weight) of chicken breast,

250 grams (raw weight) of brown rice,

300 grams of broccoli and 2 tablespoons (30 grams) of olive oil, every day.

This would equate to 1972 calories, 171 grams of protein, 205 grams of carbohydrates, and 52 grams of fat (portion sizes would be reduced for a female).

A diet consisting of these foods (in the quantities mentioned) would put someone under the recommended daily amounts of vitamin A, vitamin E, Riboflavin, vitamin B12, Folate, Calcium, Iron, Potassium, Zinc and Copper.

Clearly this is not a diet that can be labelled as ‘healthy’, and one could experience serious symptoms of deficiency such as tiredness, depression, weakness, along with internal health consequences, if the diet is maintained over long periods.

  • Cheat Days may be your kryptonite

It is not uncommon for cheat days to completely ruin the progress of one’s diet and improvements in body composition. Many individuals will spend 6 days of the week in a 500kcal daily energy deficit (=3000kcal total), and then overeat by 3000kcal on their cheat day, negating any fat loss results previously achieved. The idea of a cheat day, where you are not restricted by any dietary rules, is not necessarily a terrible idea but people should still look to control their binging if optimal results is a concern.

  • Bye Bye Social Life 

The OSBD may be the most taxing of all diets when it comes to keeping a healthy social life. Unless you are surrounded by people in similar situations as yours, you could possibly find it extremely difficult to stick to the strict eating frequency and sitting down for a meal every 2-3 hours. Day trips out may have to be cut short, unless you want to be the person who treats their Tupperware as if it were a child, and brings it with them wherever they go.

Who should run this diet?

The OSBD is suitable for people who are interested in dropping body fat whilst retaining lean muscle tissue. More specifically, the diet is ideal for individuals looking for an incredibly easy eating regime that is easy to prepare for, and does not alter food choices or quantities day to day.

The diet should not be run by individuals who are concerned with maintaining their health status whilst losing weight. People looking to not be overpowered by eating schedules, or highly restricted by dietary choice, should also look elsewhere as it can be hard to maintain a normal social life when using the OSBD.


  • Munsters M. Saris W. (2012). Effects of Meal Frequency on Metabolic Profiles and Substrate Partitioning in Lean Healthy Males. PLoS One
  • Ohkawara K, Cornier MA, Kohrt, WM, Melanson EL. (2013). Effects of Increased Meal Frequency on Fat Oxidation and Perceived Hunger. Obesity (Silver Spring)
  • Wilson, J, Wilson, GJ. (2007). Contemporary Issues in Protein Requirements and Consumption for Resistance Trained Athletes. Journal of the International Society of Sports Nutrition
  • https://www.andeal.org/vault/2440/web/200903_NAP_JADA-PositionPaper.pdf
  • Phillips, SM, Van Loon, LJ. (2011). Dietary protein for athletes: from requirements to optimum adaptation. J Sports Sci.