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Your inputs

Mifflin–St Jeor plus a transparent activity estimate.

Activity increments and deficit percentages are documented Calorie Method settings, not clinical prescriptions.

USING A DEFICIT

Choose a starting point, then evaluate the trend.

A calorie deficit means average energy intake is below average energy expenditure. The calculator estimates both; it does not measure either one.

Start with the smaller useful adjustment

The 5%, 10%, 15%, and 20% options are comparison settings created by Calorie Method. They are not prescribed by the Mifflin equation. A smaller deficit can be easier to sustain, while a larger displayed deficit can raise adequacy and adherence concerns.

Use comparable measurements

Daily body weight is affected by water, sodium, stored carbohydrate, digestion, and other factors. Compare multi-week averages collected under similar conditions. If the trend is meaningfully different from the goal after a consistent period, adjust in a small step rather than reacting to one reading.

Food quality still matters

A calorie target does not establish nutrient adequacy. Build meals around varied minimally processed foods, appropriate protein sources, vegetables and fruit, and other foods that fit individual needs and culture. Calorie arithmetic alone cannot screen for deficiencies.

Not for every situation: This tool is not designed for minors, pregnancy, breastfeeding, eating-disorder treatment, serious illness, medical nutrition therapy, or a clinician-managed diet. Seek individual care for concerning symptoms or unusually low targets.

INTERPRETATION

Four limits that prevent false precision

01

Maintenance is estimated

BMR and activity assumptions can miss an individual. Treat the output as a hypothesis.

02

Change is not linear

NIDDK’s dynamic modeling illustrates why static calorie arithmetic should not promise a fixed long-term pace.

03

BMR is not a safety line

It estimates resting energy, but this page cannot determine a personally safe or adequate intake.

04

Plateaus need context

Tracking error, changing activity, water, adherence, and adaptation can all affect the observed trend.

Sources behind the page

The resting equation is published research. Activity increments and deficit percentages are explicitly labeled product heuristics.

Mifflin et al. — resting-energy equation

Frankenfield et al. — equation comparison

CDC — gradual-change context

NIDDK — dynamic weight-change research

NIDDK — evaluating safe programs