Sure, you can lose weight on a junk food diet, since when it comes to weight loss, "it's the calories, stupid" should be the mantra. But if your goal is to live long and prosper, then (like the vegetarian Mr. Spock), you need to eat your vegetables. Yet more evidence for this comes from a study in the Archives of Internal Medicine, which looked at data from the Third NHANES Follow-up Study and found that people who consumed the highest levels of alpha-carotene (found in yellowish-orange vegetables like carrots, sweet potatoes, and pumpkins, and in dark green ones like broccoli, spinach, and lettuce) had the lowest death rates from cardiovascular disease, from cancer, and from all other causes put together.
The alpha-carotene intake was measured by blood serum levels, and the relationship was dose-dependent -- meaning, the higher the alpha-carotene level, the lower the risk. Those with a serum level of 9 µg/dL or higher had a relative risk of death that was only 61% that of those whose level was 0 to 1 µg/dL.
Alpha-carotene is chemically similar to the famous beta carotene, but seems to be more protective against certain types of cancer.
The good news is that something as simple and inexpensive as eating more fruits and vegetables can lower your risk of disease. The bad news: the CDC estimates that only 32.5% of American adults get two or more servings of fruit per day, and just 26.3% get three or more vegetables a day.