How the target is set
First the calculator estimates your maintenance calories (TDEE) with the Mifflin-St Jeor equation and an activity multiplier. Then it subtracts a daily deficit sized to the weekly pace you pick, or adds a surplus if your goal is to gain.
- Daily deficit
- pace (lb a week) × 3,500 ÷ 7
- Daily target
- TDEE − daily deficit, never below 1,200
- Weeks to goal
- pounds to go ÷ pace, rounded up
At 0.5, 1 and 1.5 lb a week the deficit is 250, 500 and 750 calories a day. These are the paces, the rounding and the floor the Dalia app uses when it builds your first plan, so the numbers match.
Picking a pace
The CDC says people who lose weight at a gradual, steady pace of about 1 to 2 pounds a week are more likely to keep it off. A slower pace is easier to live with. A faster one asks for a bigger gap between what you eat and what you burn.
Why the goal date is a rough guide
The 3,500 calories per pound rule is an approximation. Kevin Hall's analysis found it roughly matches people with more than 30 kg of body fat and overstates the deficit needed per pound for leaner people. Over months, the body also adapts: in Hall's 2011 model, body weight responds to a change in intake slowly, with half times of about a year. Expect the scale to move faster at first and slower later than a straight line says.
That is why the useful number is your trend: weigh in a few times a week, watch the average, and adjust the target if the average stops moving for a few weeks.
The 1,200 calorie floor
The calculator never shows a target under 1,200 calories a day, and neither does the Dalia app. National guidelines put typical weight-loss eating plans at 1,000 to 1,200 calories a day for women and 1,200 to 1,500 for men, and the 2013 AHA/ACC/TOS obesity guideline reserves very-low-calorie diets, under 800 a day, for medical settings with trained practitioners and monitoring. If the math puts you under the floor, the page says so and shows the floor instead.
Who this is wrong for
- Anyone under 18, pregnant or breastfeeding. Growth, pregnancy and milk production all need energy that this plan would take away.
- People with a history of an eating disorder, for whom a calorie target can do more harm than good.
- People taking a GLP-1 medication or other weight-loss drug, where appetite and intake are already changing and protein and muscle matter more. Your prescriber should guide the plan.
- Anyone whose goal weight would be a BMI under 18.5. The page flags this when it happens.
Talk to a clinician when
- The calculator shows the 1,200 floor, or your plan feels hard to sustain.
- You have diabetes, heart, kidney or liver disease, or take medication for blood sugar or blood pressure, since eating less can change how those medicines work.
- You are losing weight faster than about 2 pounds a week for more than a few weeks, or losing weight without trying.
Read more
Sources
- Losing Weight. Centers for Disease Control and Prevention.
- Hall KD. What is the required energy deficit per unit weight loss? International Journal of Obesity, 2008;32(3):573-576.
- Hall KD, et al. Quantification of the effect of energy imbalance on bodyweight. The Lancet, 2011;378(9793):826-837.
- Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults (NIH Publication No. 98-4083). National Heart, Lung, and Blood Institute, 1998.
- Jensen MD, et al. 2013 AHA/ACC/TOS Guideline for the Management of Overweight and Obesity in Adults. Circulation, 2014;129(25 Suppl 2):S102-S138.
- Mifflin MD, St Jeor ST, et al. A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition, 1990;51(2):241-247.
Other calculators
This calculator gives an estimate for general education. It is not medical advice and it is not a substitute for care from a qualified clinician. Report an error to info@daliahealth.com.