Fad diets come and go, but officially the subject of nutrition is guided by science. The public stubbornly thinks in terms of "good" foods and "bad" foods, so when the government's nutritional experts issue scientifically based advice, any attempt at a nuanced picture generally gets lost. Recently there were headlines when the highest board for dietary protocols, the Dietary Guidelines Advisory Council, reversed a government warning about avoiding foods high in cholesterol, which has been in place nearly 40 years.
The public is likely to shrug off this about-face, or else decide that eggs, the most common food high in cholesterol, is no longer a "bad" food but has moved into the "good" column. This ignores the council's message, which weighed one thing against another. For people in a normal state of health, saturated fats from animal products pose a higher risk than high cholesterol. This finding is more a shift in focus than an about-face. It's still unhealthy, the majority of nutritionists agree, to eat too much red meat as opposed to eggs, but eggs are high in saturated fat, too, so you shouldn't overdo them, either.