Why Diet Beats Exercise for Weight Loss (The Maths is Brutal)

You want to lose weight. Should you hit the gym or skip pudding? We ran the numbers using real calculators, and the maths is brutal for exercise.

The Cruel Maths of Exercise

Let's use our Calories Burned Calculator to see what it takes to burn off common foods.

To Burn Off One Chocolate Bar (250 calories)

For an 80 kg person:

Or you could just... not eat the chocolate bar. Time required: 2 seconds.

Calculate your own calories burned

To Burn Off a Takeaway Meal (1,200 calories)

A typical burger, chips, and fizzy drink:

That's an entire morning of exercise for 15 minutes of eating.

To Burn Off a Costa Frappuccino (420 calories)

Or get a black coffee. Calories: 5. Time saved: 38-75 minutes.

The Real Comparison: Exercise vs Diet

Let's say you want to create a 550-calorie daily deficit to lose 0.5 kg per week.

Option A: Burn 550 Calories Through Exercise

Using our calculator, here's what it takes EVERY SINGLE DAY:

Reality check:

• Most people don't have 50-100 extra minutes daily
• You'll be knackered
• Injury risk increases with daily intense exercise
• Exercise makes you hungry, often wiping out the calorie burn

Option B: Cut 550 Calories Through Diet

What 550 calories looks like in food:

Total time required: Zero.

***** A single decision at Tesco (not buying biscuits) prevents thousands of calories from ever entering your house. No willpower required at 10 PM when you're knackered.

The Chocolate Bar vs Running Experiment

Scenario: Lose 5 kg (38,500 calories total)

Path A: Run It Off

• Burn: ~65 calories per km for an 80 kg person
• Kilometres needed: 590 km
• At 5 km/day: 118 days of running
• Time running: ~5 hours per week

Path B: Skip the Chocolate Bars

• One chocolate bar: ~250 calories
• Bars to skip: 154 chocolate bars
• At 1 bar/day: 154 days of... not eating chocolate
• Time required: Zero

Both take similar duration, but one requires hundreds of hours of effort, the other requires nothing.

Where Exercise DOES Win

Exercise isn't useless. It's just not efficient for weight loss. Where it excels:

Exercise is for health. Diet is for weight loss.

Calculate your own weight loss plan:

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The Bottom Line

Our calculators reveal the brutal truth:

1. Eating takes seconds. Burning takes hours. A 500-calorie meal takes 5 minutes to eat and 45-100 minutes to burn off.

2. Exercise creates small deficits. Even intense daily exercise might burn 300-400 calories - less than one muffin.

3. Diet creates large deficits easily. Skipping one treat can equal an hour of running.

4. You can't outrun a bad diet. No amount of exercise compensates for unlimited eating.

Run your own numbers:

• Calories Burned Calculator - See exactly what exercise burns
• Weight Loss Calculator - Plan your timeline
• BMI Calculator - Know your target