Low Calorie Diet: Lose Weight by Reducing Calories

A low calorie diet reduces caloric intake to create a deficit. Learn how to calculate and apply this diet effectively.

Variable
Recommended duration
300-700 kcal/day
Deficit/day
0.7-1.5 lbs per week
Expected rate

Calorie calculation examples by profile

Sedentary woman, 30 years old, 154 lbs

Maintenance calories 1800 kcal
Target (with deficit) 1300 kcal
Deficit: 500 kcal/day

Active woman, 30 years old, 154 lbs

Maintenance calories 2100 kcal
Target (with deficit) 1500 kcal
Deficit: 600 kcal/day

Sedentary man, 30 years old, 187 lbs

Maintenance calories 2200 kcal
Target (with deficit) 1600 kcal
Deficit: 600 kcal/day

Active man, 30 years old, 187 lbs

Maintenance calories 2700 kcal
Target (with deficit) 2000 kcal
Deficit: 700 kcal/day

What is a low calorie diet?

A low calorie diet consists of consuming fewer calories than your body expends (TDEE). This difference creates a caloric deficit that forces the body to draw from its fat reserves. This is the fundamental principle of all weight loss, regardless of the diet followed.

Calculating your optimal deficit

For healthy weight loss, aim for a deficit of 300-700 kcal/day. A 500 kcal deficit equals a loss of about 1 lb per week. To calculate your target intake, subtract your desired deficit from your TDEE. Example: TDEE 2000 kcal - deficit 500 = 1500 kcal/day.

The basic rules

Respect minimum thresholds: 1200 kcal/day minimum for women, 1500 kcal/day for men. Below this, you risk nutritional deficiencies and muscle loss. Prioritize filling foods: proteins, fiber, vegetables. Avoid empty calories: sodas, alcohol, sweets.

Optimizing your low calorie diet

Maintain a high protein intake (1.6-2g/kg body weight) to preserve muscle mass. Spread your calories over 3-4 meals to maintain stable energy. Stay well hydrated: sometimes hunger is actually thirst. Accurate calorie tracking is essential to guarantee your deficit.

Important

Never go below 1200 kcal/day (women) or 1500 kcal/day (men) without medical supervision. Too aggressive a deficit can be dangerous for your health and counterproductive for weight loss.

Complete Guide to the Low Calorie Diet

The low calorie diet is the foundation of all weight loss. Regardless of the method chosen (keto, low carb, intermittent fasting), it’s the caloric deficit that determines whether you lose weight.

The Scientific Principle

The energy equation

  • TDEE (Total Daily Energy Expenditure): calories you burn daily
  • Caloric intake: calories you consume
  • Deficit = TDEE - Intake

Impact on weight

Deficit/dayDeficit/weekEstimated loss
300 kcal2100 kcal0.7 lbs
500 kcal3500 kcal1 lb
700 kcal4900 kcal1.4 lbs

Reminder: 3500 kcal deficit = approximately 1 lb of fat

How to Calculate Your Target Intake

Step 1: Calculate your TDEE

Use the Mifflin-St Jeor formula:

  • Men: (10 x weight kg) + (6.25 x height cm) - (5 x age) + 5
  • Women: (10 x weight kg) + (6.25 x height cm) - (5 x age) - 161

Multiply by your activity factor:

  • Sedentary: x 1.2
  • Lightly active: x 1.375
  • Moderately active: x 1.55
  • Very active: x 1.725

Step 2: Subtract the deficit

TDEE - (300 to 700 kcal) = Your daily target

Practical example

30-year-old woman, 154 lbs, 5’5”, moderately active:

  • BMR = (10 x 70) + (6.25 x 165) - (5 x 30) - 161 = 1421 kcal
  • TDEE = 1421 x 1.55 = 2202 kcal
  • With 500 deficit: 2202 - 500 = 1702 kcal/day

Thresholds to Respect

ProfileMinimumOptimal
Women1200 kcal1400-1600 kcal
Men1500 kcal1700-2000 kcal

Why respect these thresholds?

  • Prevent micronutrient deficiencies
  • Avoid excessive muscle loss
  • Maintain metabolism
  • Ensure sufficient energy

Optimize the Quality of Your Calories

Food priorities

  1. Protein (1.6-2g/kg): chicken, fish, eggs, legumes
  2. Fiber (25-30g/day): vegetables, fruits, whole grains
  3. Healthy fats: olive oil, avocado, nuts
  4. Hydration: 8-12 glasses of water per day

Foods to prioritize (high satiety)

  • Green vegetables (very low calorie density)
  • Lean proteins
  • Whole, unprocessed foods

Foods to limit (high calorie density)

  • Oils and butter (use in moderation)
  • Nuts and dried fruits (controlled portions)
  • Alcohol (empty calories)
  • Processed products

Track Effectively with Voical

Tracking accuracy is crucial on a low calorie diet. A 200 kcal/day error can cancel your deficit. With Voical, simply describe your meals out loud and get an accurate count in 15 seconds. No more random estimation, no more surprises on the scale.

Frequently asked questions