For many years, experts at the famous Cleveland Clinic have used a special ultra low-calorie, protein-rich strategy to speed off excess pounds. Called a “protein-sparing modified fast,” or PSMF diet, the plan works so well, one study found a woman can begin to reverse type 2 diabetes in four weeks and lose significant weight. “I was astonished,” recalls study head and Life Without Diabetes author Roy Taylor, MD. Is the diet hard to stick with? It can be, but a real world-friendly twist created by nutritionist Maria Emmerich can make it easier. “You get meals that are so tasty and satisfying,” says South Carolina retiree Janet Hosmer, who lost 132 pounds. “And I lost faster at age 71 than ever before.” Intrigued? Read on to see how the PSMF diet works and how you could benefit.
What is the PSMF diet?
The PSMF diet is a short-term fasting plan where you cut back to 800 calories a day and eat mostly protein. Why? Evidence is overwhelming that the fewer calories we eat, the more we lose. Yet skimping on protein causes our systems to break down muscle, leaving us weak and slowing metabolism, notes Cleveland Clinic obesity specialist Irene Dejak, MD. A PSMF menu with upwards of 60% protein “is designed to ‘spare’ or protect lean muscle so you’re only losing fat,” she explains. Metabolism and stamina stay high, which aids in long-term success.
Generally, the PSMF diet is prescribed to patients with obesity and comorbidities like high blood pressure, diabetes and heart disease. These folks typically take on a strict version of the PSMF diet, with just tiny amounts of chicken, fish and veggies a day. However, the many of us who are aiming to shed a few pounds can benefit from a more relaxed regimen.
How the PSMF diet triggers weight loss
Eating just 800 calories per day sounds daunting – but you don’t need to keep it up all week to get results. “I’ve found you only need to do PSMF one to three days a week to see a big impact on the scale,” shares Emmerich, who personally used the trick as she shed 85 pounds. She says people are amazed to lose, even after progress has been stalled for months.
The reason: In some ways, the PSMF diet works like a keto diet, lowering carbs to a point at which we don’t make enough blood sugar for fuel. “So your body makes compounds called ketones from both dietary fat and stored fat, and uses that as your fuel,” notes Emmerich. “However with PSMF, you’re eating little dietary fat, so virtually all your fuel is pulled directly from fat cells.”
In fact, dozens of studies show that short fasts can trigger beneficial shifts in our body chemistry, helping to dramatically improve levels of hormones linked to weight control and speed the production of health-promoting compounds. What’s more, it can even work to make our cells stronger by expelling defective, toxic and unneeded proteins. So you keep losing at a good pace, even on days when you’re not using the tactic, plus health soars.
How the PSMF diet staves off hunger
Concerned you’ll be starving if you try this technique? No need! Blitzing the body with protein is study-proven to slash appetite. “We have women tell us they can’t finish all the food on the plan,” Emmerich reveals. “But we tell them to try — the protein is important.” (Click through to learn how eating more protein in the morning increases weight loss.)
Worried the food will be boring? Emmerich has you covered. She suggests drizzling low-carb sauces on meat and fish and using her “wonder bread” (keep scrolling for the recipe). “The food can be lots of fun,” says Emmerich, author of 20 nutrition books, including the Protein-Sparing Modified Fast Method.
More benefits of the PSMF diet
1. Reverses type 2 diabetes
The PSMF diet is very low in calorie, which may improve the function of insulin-secreting beta cells. Since you eat so few carbs on the plan, your pancreas gets a break from pushing out sugar-balancing insulin, giving it time to refresh and recharge. Additionally, this helps to slash levels of fat in the organ, plus in the liver, making the body more efficient at burning sugar for energy when it is present. In fact, one study found that study subjects were able to entirely reverse diabetes after just four weeks of a low-calorie, PSMF-style diet.
2. Cuts cholesterol
Freeing up the liver of excess fat doesn’t just ward off diabetes — studies show it can also help tame cholesterol. That’s because less fat in the organ makes it easier for the liver to burn up the extra blood cholesterol that can send our numbers soaring. Indeed, upping protein while cutting calories does just that – and in a study at Newcastle University, researchers found that helped dieters slash cholesterol by 50% in just one week.
3. Tames high blood pressure
As weight comes down on the PSMF diet, your body has an easier time pumping blood throughout. For that reason, researchers reporting in the Journal of General Internal Medicine found that blood pressure notably drops, warding off heart disease, heart attacks and strokes.
4. Improves mood
Eating a protein-rich diet floods your body with essential amino acids that do everything from help you absorb nutrients to boost your muscle strength. Plus, they may also be essential for warding off depression, according to research in Frontiers in Psychiatry. Credit goes to the amino acid tryptophan, which researchers say is a precursor to the mood-lifting hormone serotonin. The result? Women in the study who got their fair share of protein were up to 51% less likely to experience symptoms of depression than those who ate less.
PSMF diet before and after: Janet Hosmer, 71
“At 270 pounds and only 5’4″, I was unhealthy to say the least,” recalls Janet Hosmer. After a lifetime of failed diets, the South Carolina grandmother vowed to shape up so she could enjoy retirement. At first, just cutting out sugar and flour worked well, but gradually, her progress slowed and she began to regain.
Reading about Emmerich’s PSMF strategy on Facebook, “I was convinced it would help me,” recalls Janet, an instant fan of tuna and turkey sandwiches made with Emmerich’s famous bread. “The food is really good, and there was no hunger.” Losing up to 7.8 pounds a week, Janet soon found herself 132 pounds lighter. “I have crazy energy, my arthritis is minimal, my prediabetes and fibromyalgia are gone. I feel better at 71 than I ever have!”
What to eat on the PSMF diet
To jump-start huge results, 1 to 3 days a week, limit yourself to 800 calories, 30 to 35 grams of fat and very few carbs. Skip nuts and dairy on fast days. Use a free app like CarbManager.com to hit your targets. On non-fasting days, Emmerich recommends a traditional keto diet that allows for 1 to 2 servings of fat per sitting and up to 20 grams of carbs per day. Always get a doctor’s okay to try a new diet. (Click through for our tips on how to prep for a fast.) Here are some meal ideas to get you started:
BREAKFAST: Prepare 4 egg whites with herbs, optional 1 ounce lox or very lean sausage and cooking spray.
LUNCH: 4 ounces chicken breast cooked in 1 teaspoon coconut oil; drizzle with 2 tablespoons keto barbecue sauce.
DINNER: 4 ounces lean beef and 1 egg white prepared with cooking spray, herbs, and salt and pepper.
Bonus recipe: Maria’s Famous Egg-White Bread
This recipe is nearly 100% protein and tastes a lot like Wonder Bread
- 12 large egg whites
- 1 cup unflavored egg white protein powder, such as Jay Robb brand
- With mixer, whip egg whites until very stiff peaks form, about 10 minutes. With rubber spatula, slowly fold in protein powder. Then scrape dough in greased loaf pan.
- Bake at 325ºF until golden brown, 40–45 minutes. Let cool fully (or bread will collapse). Cut 14 slices. (Calories: 40; Protein: 9 grams; Carbs: .5 grams per slice.) Store in airtight container in fridge for up to 6 days. For a meal, add 4 oz. lean turkey and 2 Tbs. mustard.
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A version of this article originally appeared in our print magazine, Woman’s World.