Rules for writers, Tenth edition - Diana Hacker, Nancy Sommers 2021

Develop the main point
Writing paragraphs
A process for writing

Though an occasional short paragraph is fine, particularly if it functions as a transition or emphasizes a point, a series of brief paragraphs suggests inadequate development. How much development is enough? That varies depending on the writer’s purpose and audience.

For example, when Jane Brody, a health columnist, wrote a paragraph to convince readers that it is impossible to lose fat quickly, she knew that she would have to present a great deal of evidence because many dieters want to believe the opposite. If her paragraph was underdeveloped and light on evidence, she would not be able to persuade her readers and would leave them with more questions than answers. If Brody had left her paragraph at these few sentences, it would not be sufficient:

UNDERDEVELOPED PARAGRAPH

When you think about it, it’s impossible to lose — as many diets suggest — 10 pounds of fat in ten days, even on a total fast. Even a moderately active person cannot lose so much weight so fast. A less active person hasn’t a prayer.

This three-sentence paragraph states her main point but does not contain enough information to back it up. The paragraph that Brody did write builds on the main point and contains enough evidence to convince even skeptical readers:

WELL-DEVELOPED PARAGRAPH

When you think about it, it’s impossible to lose — as many . . . diets suggest — 10 pounds of fat in ten days, even on a total fast. A pound of body fat represents 3,500 calories. To lose 1 pound of fat, you must expend 3,500 more calories than you consume. Let’s say you weigh 170 pounds and, as a moderately active person, you burn 2,500 calories a day. If your diet contains only 1,500 calories, you’d have an energy deficit of 1,000 calories a day. In a week’s time that would add up to a 7,000-calorie deficit, or 2 pounds of real fat. In ten days, the accumulated deficit would represent nearly 3 pounds of lost body fat. Even if you ate nothing at all for ten days and maintained your usual level of activity, your caloric deficit would add up to 25,000 calories. . . . At 3,500 calories per pound of fat, that’s still only 7 pounds of lost fat.

— Jane Brody, Jane Brody’s Nutrition Book