The Calculus of Happiness: How a Mathematical Approach to Life Adds Up to Health, Wealth, and Love

Preface ix
Math Topics Covered by Chapter xiii
I: A Healthier You Is Just a Few Equations Away 1
1 How Many Calories Should You Eat Each Day? 3
1.1 The Linear Functions Hidden in Your Diet 4
1.2 The Mathematics of Metabolism 8
1.3 Burn Those Calories! Work Those Quads! 11
1.4 The Calories Required to Digest Food 14
2 Live Longer (and Be Healthier) by Eating the Right Foods 20
2.1 A Game of Macronutrient Musical Chairs 20
2.2 How to Eat More and Be Healthier: Energy Density 29
2.3 Live Long(er) and Prosper with theWaist-Height Ratio 34
II: A Mathematician's Guide to Managing Your Money 41
3 Dissecting Your Monthly Budget 43
3.1 The Return of the King (the Linear Function) 44
3.2 To Expenses, and Beyond! 49
3.3 How Many YearsWill It Take You to Reach Financial Independence? 62
4 How to Beat Wall Street at Its Own Game 69
4.1 How to Make 15% a Year, Guaranteed 70
4.2 The Safest Investments 71
4.3 Quantifying Investment Risk and Return 73
4.4 Stocks, Bonds, and the "All-Weather" Portfolio 77
III: Looking for Love? There May Be an Equation for That 87
5 Finding "The 1" 89
5.1 What the Search for Aliens Can Teach You about FindingYour Soulmate 89
5.2 Why Hiring a Secretary Is Like Dating 92
5.3 The Stable Matching Problem 97
6 Living Happily Ever After with "The 1" 103
6.1 Your Relationship as a Dynamical System 104
6.2 Need Help Making a Joint Decision? There's an Equation for That 108
6.3 How Psychologists Use Math to Predict Divorce 113
Epilogue 118
Acknowledgments 120
Appendix A: Background Content 121
Appendix 1 123
Appendix 2 128
Appendix 3 130
Appendix 4 141
Appendix 5 143
Appendix 6 144
Bibliography 151
Index 157

Oscar E. Fernandez is associate professor of mathematics at Wellesley College. He is the author of Everyday Calculus and The Calculus of Happiness (both Princeton).