The Claim

Among obese adults, initiation of the protein-sparing modified fast (PSMF) results in 6% greater average weight loss at one year compared to other diets, but this difference is no longer present by year four.

Source: The Effect of Starting the Protein-Sparing Modified Fast on Weight Change over 5 years

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
59score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Quantitative
1 study reviewed
In plain English

Obese adults who start the protein-sparing modified fast lose 6% more weight than those on other diets after one year, but by four years, both groups have lost the same amount of weight.

See the scientific wording

Among obese adults who initiate the protein-sparing modified fast (PSMF), average weight loss is 6% greater than those choosing other diets at one year, but this difference disappears by year four, indicating rapid initial weight loss that is not sustained long-term.

Why this might work

When someone starts the protein-sparing modified fast, the body quickly breaks down fat stores for energy because there is very little food intake. This causes fast weight loss at first. But after a while, the body slows down how much energy it uses, and hunger increases, so the person eats more or moves less, and weight loss stops.

Supported mechanismbased on 1 study

What the research says

1 study
  1. Study: The Effect of Starting the Protein-Sparing Modified Fast on Weight Change over 5 years

    People who tried the PSMF diet lost weight faster in the first year than those on other diets, but by the fourth year, everyone had lost about the same amount — so the early advantage didn’t last.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.