"Sustained walking sessions for a minimum period of thirty to sixty minutes a day, five days a week, with the correct walking posture, reduces health risks and has various overall health benefits, such as reducing the chances of cancer, type 2 diabetes, heart disease, anxiety and depression. Life expectancy is also increased even for individuals suffering from obesity or high blood pressure. Walking also increases bone health, especially strengthening the hip bone, and lowering the more harmful low-density lipoprotein (LDL) cholesterol, and raises the more useful good high-density lipoprotein (HDL) cholesterol.

Studies have found that walking can also prevent dementia and Alzheimer's."

From Wikipedia: Health Benefits of Walking. Click to see sources.

The direct yearly medical cost of being obese in the U.S. is $1,723 per obese person. Being overweight is a bargain at $266.

According to the CDC (source) 33.8% of U.S. adults are obese, an additional 34.4% of U.S. adults are overweight.

From Direct medical cost of overweight and obesity in the USA: a quantitative systematic review in Obesity Reviews.

Walking is a fantastic way to lose weight. Calories burned while walking

Elephants are the heaviest land animal on the planet. Elephants at Wikipedia