Thread by @WellBuiltStyle

I’m not a big fan of crash dieting…

But if you went a little overboard on summer vacation and need to quickly drop some body fat and get back on track, it’s worth looking into a CLASSIC protocol from Lyle McDonald: the Protein Sparing Modified Fast (PSMF).

Here’s how it works...

I should mentioned Lyle first published this protocol in 2005 and then updated it in 2008...keep in mind this is a rapid fat loss plan, it's meant as a short-term kickstart, not a long-term diet.

You're supposed to switch to a more sustainable approach after 10-12 days.

Here's how it works:

✔️You eat a high protein diet – anywhere between 1-2g of protein per pound of body weight per day. Focus here is on LEAN sources - think chicken breast, tuna, shrimp, whey protein, egg whites, non fat Greek yogurt etc.

✔️Supplement with fish oil – 1g of of EPA/DHA is plenty

✔️Take a basic multi vitamin/multimineral supplement

✔️Include some non starchy veggies for fiber and to keep hunger somewhat at bay

For resistance training on PSMF, aim for 3–4 days per week, but cut your volume way down, about one-third of what you normally do for each muscle group.

Example: if you usually hit chest for 12 total sets per week, drop it to 4 sets.

The key is to keep intensity HIGH. Take your sets close to, or all the way to, failure.

Stick to compound lifts (multi-joint movements) as your foundation. Barbells, dumbbells, and machines are all fair game.

Aerobic training is fine to include (but not necessary) just keep it low-intensity, Zone 2 cardio. 30-60 min sessions a few times per week.

What about eating carbs and fats?

Nada.

It’s called a Protein Sparing Modified Fast for a reason because all you’re really eating protein.

The only exception is having a small amount of fast digesting carbs (~30g or so) before training for a little fuel.

On PSMF, don’t be shocked if you’re averaging 800-1,200 calories per day.

It’s meant to be very low calorie and only for a short run (10–12 days) to drop a solid chunk of fat.

How much can you lose? It depends on your weight, body fat, and deficit.

For example, let's say...

You weight 200 lbs at 20% body fat

Protein: 1g/lb = 200g = ~800 calories

Add ~30g carbs pre-workout + non-starchy veggies = ~1,000 calories/day

Let's say your maintenance is ~2,500 calories/day...therefore you're creating a 1,500 calorie daily deficit

Over 10 days that would amount to roughly a 15,000 calorie deficit which would translate to about ~4 lbs fat loss.

That's not too shabby.

Remember, this isn't a LONG TERM solution. You won't be able to sustain it.

It's just a short term "crash diet" to get the wheels in motion. The cycle is supposed to last between 10-12 days before you take a break or move on to a more sustainable approach.

I remember doing this many years ago and found it very effective.