PSMF – Protein Sparing Modified Fast

PSMF stands for Protein Sparing Modified Fast.

A PSMF is a temporary diet to kick-start rapid weight loss in people who are already severely obese or for people that are very lean, in-shape and need to lose those last few pounds be it stubborn body fat or just the last few pounds when trying to reach their goal weight. A PSMF is often used the last few weeks before a photo shoot, vacation (hitting the beach), fitness shows, etc or to break a stall. A PSMF should NOT be considered a long term solution but more of a safe-crash-dieting method for hitting very low body fat levels.

The basic premise is LOW fat, LOW carbs and HIGH protein. It is basically a ketogenic diet because of the low carbs (30gms or less) but varies in design of a true keto/high-fat set up in that the fat intake is drastically reduced. Both a PSMF and a ketogenic diet will put ones body in ketosis and fat will be the bodies preferred fuel source.

The reason why a PSMF works so well is because on a ketogenic diet your body burns fat for its fuel/energy and if you do not provide the body with adequate fat (from food intake) the body is forced to use up stored body fat at a RAPID rate, hence why the PSMF is so effective for fat loss.

The protein intake is kept HIGH to preserve muscle mass, and it does very well.

Example of macro breakdown of a 200lb person with 10% body fat (180lbs lean mass):

15-30gms of carbs
15-30 gms of fat (be sure to include 10gms of fish oil in that total)
1.5gms-2gms of PROTEIN per pond of lean mass so 270-360gms. These numbers are for those on the high end of the activity level (cardio and weights). Other people can get by with 1-1.5gms per pound of lean mass.

From what I have seen, your daily caloric total will probably be 50-60% of what you are normally used too. My normal cals vary from 1800-2300, on a PSMF its around 1200-1400.

** Recommended supplements for a PSMF diet: **

Some pretty basic but much needed supplements while following a PSMF:

Fish Oil – The PSMF Diet lacks in essential fatty acids(also know as EFA’s), so a supplement will be needed. Most recommend up to 10,000mg/day. KetoGenics Mega EPA/DHA is a triple strength fish oil product and a great price.

A Multivitamin/Multi-mineral supplement: The lack of fruit combined with limited vegetables could lead to vitamin deficiencies especially the longer you are on the diet. Play it safe and take a multivitamin/mineral supplement when following a PSMF. Keto Multi-Vit would be a good choice in this regard.

Electrolytes: Sodium/Potassium/Magnesium should be added to any keto or low-carb diet and even more so on a PSMF – typically it is recommended to supplement with 3-5 g of sodium, 1 g of potassium (most pills come in 99mg amounts), 500 mg of magnesium, this should help with fatigue. In addition 600-1000mg/day of calcium is also recommended. An all in one like Keto-Lytes would fit in perfect here.

In addition some will find taking both Ket-Lytes and a Multi Mineral complex covers their bases very well.

Fiber: If you are not getting enough from eating fibrous veggies (broccoli, cauliflower, etc) which is usually the case on a PSMF then adding in some Pysllium fiber is a great help.. Sugar free Metamucil or Pysllium fiber capsules work wonders. Check out KetoGenics Pysllium fiber capsules.

ECA stack (Ephedrine, Caffeine, Aspirin) – Ephedrine is no longer legal but it was amazing for blunting hunger, giving you tons of energy as well as the most researched “far burner” in decades. Luckily there is a better alternative available called Betadrine ECA which has become super popular among the PSMF community; feedback is that it works much better than the ECA stack.  You can check it out here: BetadrineECA or 

Protein Powder: Many have no issues with using them and find they are needed to hit their daily protein total but are not very satiating so if you want to use some then try to get micellar casein which will have a better chance of filling you up vs whey. For PSMF, casein is better than whey because it digests slowly and is more filling.

Exercise: keep it simple, weights – cut the intensity and frequency in half. Same thing for cardio, most do not even need to do cardio on a PSMF but if you must keep it short or do some LISS on the treadmill (Low Intensity State State cardio).

If you really want to succeed on a PSMF then I HIGHLY recommend you buy Lyle McDonald’s “Rapid Fat Loss Handbook”

Lye has brought this diet to the mainstream and has a HUGE following among bodybuilders and fitness enthusiasts.