I have seen more than one study challenging the utility - and even sensibility - of recommending an increase in the consumption of fruits and vegetables as a means to maintain or lose weight. In the US, the recommendation is either just a general eat more or a more specific eat at least 5 servings. In other countries, for example Australia, the recommendation is 2 fruits and 5 vegetables. Walter Willett and the folks at HSPH recommend more vegetables than fruit.
To be clear, non-starchy vegetables, specifically, and some fruits have been shown to improve health, possibly through their antioxidant properties. But recently, using Eat More Fruits and Vegetables as an obesity prevention/treatment strategy, has come into question. I have been concerned about the recommendation for some time, and that is why I promote Willett’s new food pyramid over the USDAs food guidance.
My concerns about fruit and vegetable promotion and all food related promotion is that people don’t hear, because its seldom said, eat more of this (x) INSTEAD of that (x). People do not get the message that adding health promoting foods such as fruits, vegetables, whole grains, healthy oils, fish, etc. needs to be qualified. The healthy foods are particular and only stay healthy if they remain nutrient dense (e.g., potatoes are a starchy vegetable which we do NOT need to increase, and kale is GREAT, kale cooked in fat back/butter is NOT GREAT).
Of course, fruits and vegetable calories are of a higher nutritional value than ones from chips, hotdogs and soda, but 1) the choice of fruit (e.g., a plum vs kiwi) or vegetable, 2) the preparation of that fruit or vegetable, 3) the size of that fruit or vegetable (i.e., jumbo fruits (bananas, oranges, apples = 2 or 3 servings), and 4) the overall amount of calories consumed will determine if adding fruits and vegetables to ones diet aids in weight loss. The bulky, nutritious, fiber rich peppers, summer squash, onions and mushrooms should bulk up one's plate and reduce the caloric density of a meal– these foods should replace (or reduce) meat and pasta for instance.
Two studies released this month,(Charlton et al., 2014; Kaiser et al., 2014), found that increasing fruit and vegetable intake did not lead to weight loss and in some instances, led to weight gain. The Kaiser et al study used robust criteria to evaluate randomized control trials (RCT) and though the RCTs themselves had limitations, the review of them was sound. In the authors’ words, the upshot is this….
Purchasing and preparation barriers need to be addressed. Interventions should provide more instruction on how to prepare vegetables in such a way as to not increase their energy content (such as not preparing vegetables with fat (eg not frying or serving with butter)… and….Although many fruits and vegetables [F/V] have demonstrable positive health benefits, recommending increased F/V consumption to treat or prevent obesity without explicitly combining with methods to reduce intake of other energy sources is unwarranted (Kaiser, et al).
One of the main reasons I started my You Tube channel was to show people how to cook foods without turning them into calorically dense meals or snacks. So, do eat more fruits and vegetables as you eat LESS meats, breads, and desserts.
Charlton, K., Kowal, P., Soriano, M. M., Williams, S., Banks, E., Vo, K., & Byles, J. (2014). Fruit and Vegetable Intake and Body Mass Index in a Large Sample of Middle-Aged Australian Men and Women. Nutrients, 6(6), 2305-2319.
Kaiser, K. A., Brown, A. W., Brown, M. M. B., Shikany, J. M., Mattes, R. D., & Allison, D. B. (2014). Increased fruit and vegetable intake has no discernible effect on weight loss: a systematic review and meta-analysis. The American journal of clinical nutrition, 100(2), 567-576.