The Claim

In healthy adults, consuming protein or carbohydrate preloads prior to meals has no significant effect on total daily energy intake, energy expenditure, or net energy balance over a 5-day period under ad libitum dietary conditions.

Source: A randomized cross-over trial to determine the effect of a protein vs. carbohydrate preload on energy balance in ad libitum settings

What the research says

Supports is higher

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

Supports
88score
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.

Description
1 study reviewed
In plain English

Eating protein or carbohydrate snacks before meals does not change how many calories people consume in a day, how many calories they burn, or their overall energy balance over five days when eating freely.

See the scientific wording

In healthy adults, consuming protein or carbohydrate preloads prior to meals does not significantly alter total daily energy intake, energy expenditure, or net energy balance over a 5-day period, indicating that short-term macronutrient manipulation via preloads does not influence overall energy balance in ad libitum settings.

Why this might work

When protein is eaten before a meal, the body burns more calories digesting it, but people eat the same amount of food afterward and their overall calorie burning stays the same, so total energy balance doesn't change.

Verified mechanismbased on 1 study

What the research says

1 study
  1. Study: A randomized cross-over trial to determine the effect of a protein vs. carbohydrate preload on energy balance in ad libitum settings

    Adding protein or sugar shakes before meals didn’t make people eat more or less food, or change how many calories they burned overall—even though protein made their bodies burn a little extra energy right after eating. So, it didn’t help them lose weight or gain weight over five days.

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.