1. Can eating fruits and vegetables help people to manage their weight?

2. There are many proposed strategies for losing or maintaining weight. This presentation looks at only one strategy: substituting low-energy-dense fruits and vegetables for foods with high energy density in order to lower the number of calories consumed. References to all studies are in “Can fruits and vegetables help people to manage their weight?” in the CDC Web site: www.cdc.gov/nccdphp/dnpa and in the notes in this electronic PowerPoint presentation. www.cdc.gov/nccdphp/dnpa

3. What Is Energy Density? It is the relationship of calories to weight of food (i.e., calories per gram). All foods are in one of three categories:  High-energy-dense foods: 4-9 calories per gram (e.g., cookies, crackers, butter, bacon)  Medium-energy-dense foods: 1.5-4 calories per gram (e.g., bagels, dried fruits, hummus, part-skim mozzarella)  Low-energy-dense foods: 0.0-1.5 calories per gram (e.g., most fresh fruits and vegetables, fat-free yogurt)

4. Dietary Guidelines for Americans (2005) “…calorie-lowering strategies include eating foods that are low in calories for a given measure of food (e.g., many kinds of vegetables and fruits and some soups).” “…make substitutions to avoid excessive calorie intake.”

5. Volume, Density, and Calories in Weight Management  Feeling full is one reason people stop eating.  Volume affects the feeling of being full.  Low-energy-dense foods have fewer calories than the same volume of high-energy-dense foods. People who eat low-energy-dense foods can feel full while eating fewer calories.  Water and fiber increase volume and reduce energy density.  Fruits and vegetables have high water and fiber content and are relatively low in calories and energy density. Conclusion: Fruits and vegetables are good substitutes for high-energy-dense foods in a weight management program.

6. So how do people lose weight?  To lose weight people must consume fewer calories than they expend. Eating fewer calories is difficult, but feeling full is one reason that people stop eating.  The amount or volume of food a person eats prompts a feeling of being full.

7. One study* provides evidence that feeling full is more likely to make a person stop eating than the total calories consumed.  For 5 days, 20 participants ate as much as they wanted from food offered to them over 5 days.  The diet alternated from low-energy-dense to high-energy-dense foods. Result: The participants felt full on the low-energy- density diet after eating just over half the calories (1570 kcal) they consumed before feeling full on the high-energy-density diet (3000 kcal). * Duncan KH, Bacon JA, Weinsier RL. The effects of high and low energy density diets on satiety, energy intake, and eating time of obese and nonobese subjects. Am J Clin Nutr 1983;37:763-7.

8. Eating low-energy-dense foods = Fewer calories consumed than when eating high-energy-dense foods, but feeling equally full  For 2 days, researchers provided meals and snacks for 2 days to women who were assigned to a low-, medium-, or high-calorie menu.  The women in each group ate until they were full.  All groups of women ate a similar amount, or volume, of food.  The study suggests that the volume of food, not calories, makes people feel full. Bell EA, Castellanos VH, Pelkman CL, Thorwart ML, Rolls BJ. Energy density of foods affects energy intake in normal-weight women. Am J Clin Nutr 1998;67:412-420.

9. Volume affects energy density and the feeling of being full.*  Yogurt milkshakes were given 30 minutes before lunch on 3 different days.  The shakes came in three sizes: 300 ml, 450 ml, and 600 ml, BUT had equal calories.  (Higher volumes were achieved by incorporating air.)  Participants consumed 12% fewer calories at lunch after drinking the 600 ml milkshake.  Participants reported greater feelings of fullness after drinking the 450 ml milkshake or the 600 ml milkshake than after the 300 ml drink. * Rolls BJ, Bell EA, Waugh BA. Increasing the volume of a food by incorporating air affects satiety in men. Am J Clin Nutr 2000;72:361-368.

10. Water, Energy Density, and the Feeling of Being Full On 3 different days during a 4-week study*  24 women ate the same foods over 3 days, but prepared differently each day  Day 1: chicken-rice casserole (1 1/3 cups).  Day 2: chicken-rice casserole (1 1/3 cups) with a glass (8 oz.) water.  Day 3: chicken-rice soup (2½ cups) made by adding 8 oz. water into the casserole ingredients used the previous day. Eating the soup (compared to the foods on other days) - Significantly increased the feeling of being full. - Reduced the participants’ hunger. - Significantly reduced the number of calories the women consumed during lunch. *Rolls BJ, Bell EA, Thorwart ML. Water incorporated into a food but not served with a food decreases energy intake in lean women. Am J Clin Nutr 1999;70:448-55.

11. A literature review* found similar findings:  Short-term studies: Low-energy-dense foods promoted feeling full, reduced hunger, and provided fewer calories.  Long-term studies: Low-energy-dense foods promoted moderate weight loss.  Studies lasting longer than 6 months: Weight loss was three times greater for people who ate foods of low energy density than for those who simply ate low-fat foods. *Yao M, Roberts SB. Dietary energy density and weight regulation. Nutr Rev 2001;59:247-58.

12. Fruits and Vegetables = Low Energy Density  Fat increases the energy density of foods.  Water and fiber in foods increase volume and reduce energy density.  In their natural state, fruits and vegetables have high water and fiber content and are low in fat and energy density. The USDA’s Web site on food composition (www.nal.usda.gov/fnic/foodcomp) lists water and fiber content, as well as other food components, including calories, for hundreds of vegetables and fruits.www.nal.usda.gov/fnic/foodcomp

13. Studies* with fruit and fruit juices show:  Whole fruit is more satiating.  Whole fruit contains fiber, and juice is fiber-free. *Haber GB, Heaton KW, Murphy D, Burroughs LF. Depletion and disruption of dietary fibre. Effects on satiety, plasma-glucose, and serum insulin. Lancet 1977;2:679-88. *Bolton RP, Heaton KW, Burroughs LF. The role of dietary fiber in satiety, glucose, and insulin: studies with fruit and fruit juice. Am J Clin Nutr 1981;34:211-17.

14. Vegetables, Fiber, Water, and Feeling Full In a series of studies* by Gustafsson and colleagues:  Researchers found that adding vegetables (carrots and spinach) to meals but keeping the same number of calories enhanced the feeling of being full if at least 200 g of vegetables were added.  Ratings of fullness were correlated positively with the fiber content, water content, and total weight of the meal. *Gustafsson K, Asp N-G, Hagander B, Nyman M. Effects of different vegetables in mixed meals on glucose homeostasis and satiety. Eur J Clin Nutr 1993;47:192-200. Gustafsson K, Asp N-G, Hagander B, Nyman M. Dose-response effects of boiled carrots and effects of carrots in lactic acid in mixed meals on glycaemic response and satiety. Eur J Clin Nutr 1994;48:386-96. Gustafsson K, Asp N-G, Hagander B, Nyman M. Satiety effects of spinach in mixed meals: comparison with other vegetable Int J Food Sci Nutr 1995:46:327-34. Gustafsson K, Asp N-G, Hagander B, et al. Influence of processing and cooking of carrots in mixed meals on satiety, glucose and hormonal response. In J Food Sci Nutr 1995;46:3-12.

15. Dietary Fiber and Weight Management  In a review* of 22 studies, 20 studies found that high- fiber diets resulted in weight loss.  Even in studies that did not restrict food intake, participants on high-fiber diets lost significantly more weight than those on the low-fiber diets.  An increase of 14 g of fiber per day was associated with an average weight loss of more than 4 lb. within nearly 4 months, based on pooled data from 12 studies. *Howarth NC, Saltzman E, Roberts SB. Dietary fiber and weight regulation. Energy density of foods affects energy intake across multiple levels of fat content in lean and obese women. Am J Clin Nutr 2001;73:1010-18.

16. Review* of Dietary Intervention Studies Many studies have found that significant weight loss can occur when advice to increase the intake of fruits and vegetables is coupled with advice to reduce energy intake. *Rolls BJ, Ello-Martin JA, Tohill BC. What can intervention studies tell us about the relationship between fruit and vegetable consumption and weight management? Nutr Reviews 2004;62:1-17.

17. Intervention 1: MRFIT* Multiple Risk Factor Intervention Trial  Participants were advised to reduce their fat intake and increase consumption of fruits and vegetables and whole grains to help them lose weight and improve their blood lipids and blood pressure.  Increases in fruit and vegetable intake were related to maintenance of weight loss.  Participants who lost more weight ate more fruits and vegetables than the others. *Dolecek TA, Stamler J, Caggiula AW, et al. Methods of dietary and nutritional assessment and intervention and other methods in the Multiple Risk Factor Intervention Trial. Am J Clin Nutr 1997;65(suppl 1):196S-201S.

18. Intervention 2: Reduced Calories, Low Fat, and High Complex Carbohydrates*  Allowed unlimited fruits and vegetables for 6 months.  147 (69%) of the 213 adult participants lost weight (average: 14 lb).  During 25 months of follow-up— - 53% of the participants continued to lose or maintain their weight. - The mean net weight loss from pretreatment to the end of follow-up was more than 17 lb. *Fitzwater SL, Weinsier RL, Wooldridge NH, et al. Evaluation of long-term weight changes after a multidisciplinary weight control program. J Am Diet Assoc 1991;91:421-4.

19. Intervention 3: Families with Obese Parents and a Nonobese Child*  Parent-focused behavioral intervention.  Two groups: Both had a comprehensive behavioral program. - One group increased fruit and vegetable consumption. - Second group decreased their intake of high-fat and high-sugar foods.  Materials for the children targeted the same dietary changes as for their parents, but with no calorie restrictions. After 1 year: - Parents in the increased fruit and vegetable group experienced greater decreases in weight than parents in the decreased fat and sugar group. - Parents and children in the increased fruit and vegetable group also decreased consumption of high-fat and high-sugar foods. *E pstein LH, Gordy CC, Raynor HA, Beddome M, Kilanowski CK, Paluch R. Increasing fruit and vegetable intake and decreasing fat and sugar intake in families at risk for childhood obesity. Obesity Res 2001;9(3):171-8.

20. Intervention 4: Increased Fruits and Vegetables with Decreased Fat Intake*  Participants consumed a daily diet that included specific amounts of fruits, vegetables, juice and fiber, and provided 15%-20% of energy from fat. After 1 year:  Energy-adjusted intake of vegetables and dietary fiber, but not fruit, was associated with a decrease in body mass index (BMI).  A decrease in percent energy from fat was not associated with a drop in BMI. *Rock CL, Thomson C, Caan BJ, et al. Reduction in fat intake is not associated with weight loss in most women after breast cancer diagnosis: evidence from a randomized controlled trial. Cancer 2001;91:25-34.

21. Intervention 5: Polyp Prevention Trial* Participants who increased their intake of fruits and vegetables and decreased their fat intake lost a significant amount of weight in 1 year. *Lanza E. Schatzkin A, Daston C, et al. Implementation of a 4-y, high-fiber, high-fruit-and-vegetable, low-fat dietary intervention: results of dietary changes in the Polyp Prevention Trial. Am J Clin Nutr 2001;74:387-401.

22. Intervention 6: Cardiac Trials— Lower Fat and Increased Fruits and Vegetables In a series of trials, cardiac patients who changed their diets by lowering their fat intake and increasing their consumption of fruits and vegetables lost a significant amount of weight. *Singh RB, Rastogi S, Verma R, et al. Randomised controlled trial of cardioprotective diet in patients with recent acute myocardial infarction: results of a one year follow up. Br Med J 1992;304:1015-9. Singh RB, Rastogi S, Niaz MA, et al. Effect of fat-modified and fruit- and vegetable-enriched diets on blood lipids in the Indian Diet Heart Study. Am J Cardiol 1992;70:869-74. Singh RB, Dubnov G, Niaz MA, et al. Effect of an Indo-Mediterranean diet on progression of coronary artery disease in high risk patients (Indo-Mediterranean Diet Heart Study): a randomized single-blind trial. Lancet 2002;360:1455-61.

23. Research Review  Very few studies examined a direct relationship between eating fruits and vegetables and losing weight.  Some studies had few participants.  Many studies focused on fruits and vegetables in the context of treating high blood pressure or cardiac disease—but also reported on weight loss.  Some studies examined the short-term impact of eating fruits and vegetables on energy intake.

24. Summary:  Feeling full cues people to stop eating.  People feel full based on the volume of food consumed, not necessarily on the number of calories in the food.  Eating low-energy-dense foods can help people feel full with fewer calories.  Replacing foods of high energy density (high calories per weight of food) with foods of low energy density, such as fruits and vegetables, can be an important part of a weight management strategy.

25. Tips for Eating Fruits and Vegetables in a Weight Management Program  Fruits and vegetables should be substituted for foods high in energy density.

26. Tips for Eating Fruits and Vegetables in a Weight Management Program  To lower the energy density of foods, such as soups, sandwiches, and casseroles, substitute fruits and vegetables for some of the ingredients that have higher energy density, such as high-fat meat, cheese, and pasta.

27. Tips for Eating Fruits and Vegetables in a Weight Management Program:  Breading and frying vegetables or adding high- fat dressings and sauces greatly increase the calorie and fat content of the dish.  Some desserts that include fruit may also have high calorie, fat, and sugar content.

28. Tips for Eating Fruits and Vegetables in a Weight Management Program  Eat whole fruit instead of drinking juice.  Frozen and canned fruits and vegetables are good options when fresh produce is not available. Choose items without added sugar, syrup, cream sauces, or salt.

29. Tips for Eating Fruits and Vegetables in a Weight Management Program  Vegetables tend to be lower in calories than fruit. Substituting more vegetables than fruit for foods of higher energy density can be helpful in a weight management plan.

30. Types of Fruits  Fruit is the sweet, fleshy, edible portion of a plant. It generally contains seeds. Fruits are usually eaten raw, although some varieties can be cooked. They come in a wide variety of colours, shapes and flavours. Common types of fruits that are readily available include:  Apples and pears  Citrus – oranges, grapefruits, mandarins and limes  Stone fruit – nectarines, apricots, peaches and plums  Tropical and exotic – bananas and mangoes  Berries – strawberries, raspberries, blueberries, kiwifruit and passion fruit  Melons – watermelons, rock melons and honey dew melons  Tomatoes and avocados.

31. Types of Vegetables  Vegetables are often cooked, although some kinds (salad vegetables) are eaten raw. Vegetables are available in many varieties and can be classified into biological groups or ‘families’, including:  Leafy green – lettuce, spinach and silverbeet  Cruciferous – cabbage, cauliflower, brussel sprouts and broccoli  Marrow – pumpkin, cucumber and zucchini  Root – potato, sweet potato and yam  Edible plant stem – celery and asparagus  Allium – onion, garlic and shallot.

32. Legumes  Legumes or pulses contain nutrients that are especially valuable. Legumes need to be cooked before they are eaten – this improves their nutritional quality, aids digestion and eliminates any harmful toxins. Legumes come in many forms including:  Soy products – tofu (bean curd) and soybeans  Legume flours – chickpea flour (besan), lentil flour and soy flour  Dried beans and peas – haricot beans, red kidney beans, chickpeas and lentils  Fresh beans and peas – green peas, green beans, butter beans, broad beans and snow peas.

33. Colour is the key to healthy food  Maximum health and protection against disease comes from eating a wide variety of fruits and vegetables. The National Health and Medical Research Council (NHMRC) guidelines recommend that adults eat at least five kinds of vegetable and two kinds of fruit every day.

34. Continue…  Foods of similar colours generally contain similar protective compounds so try to eat a rainbow of colourful fruits and vegetables every day to get the full range of health benefits. For example:  Red foods – like tomatoes and watermelon contain lycopene, which is thought to be important for fighting prostate cancer and heart disease.  Green vegetables – like spinach and kale contain lutein and zeaxanthin, which may help protect against age-related eye disease.  Blue and purple foods – like blueberries and eggplant contain anthocyanins, which may help protect the body from cancer.  White foods – like cauliflower contain sulforaphane, which may also help protect against some cancers.

35. Things to Remember  Fruits and vegetables contain important vitamins, minerals and ‘plant chemicals’.  There are many varieties of fruit and vegetables available.  Eat 5 kinds of vegetable and two kinds of fruit every day for good health.  A diet high in fruit and vegetables can help protect against cancer, diabetes and heart disease.

36. Right Way to Cook Vegetables  You go out of your way to buy the freshest, peak- season vegetables, not only because they taste good but also because they’re packed with vitamins, minerals, and antioxidants. But did you know that how you cook them makes a huge difference in how well they retain those nutrients? Some cooking methods preserve nutrients and even help them enter your bloodstream, while others can destroy them. So once you get those vegetables home from the market, look to the strategies here to get the most nutritional bang for your buck.

37. Limit the Water  When you cook vegetables in water, you lose nutrients. You know that green hue the water takes on after you’ve boiled or blanched your broccoli? That’s a sign that vitamins like C and B have leached into the water, only to be poured down the drain. To retain these vitamins, cook vegetables in as little water as possible for a minimal amount of time (unless you’re planning to consume the water, as in a soup).

38. Continue…  Steaming and microwaving, both of which use little water, will give you the same results as boiling or blanching but with much less nutrient loss. So instead of boiling potatoes before mashing them, steam them. Instead of blanching broccoli, green beans, or asparagus, steam or microwave them until crisp-tender.

39. Continue…  Similarly, if you want your vegetables cooled, don’t plunge them into an ice bath; like hot water, cold water can also leach nutrients. Instead, cook vegetables for a minute less and then spread them in a single layer on a baking sheet so they’ll cool quickly at room temperature.

40. Use a Little Fat  Eating plain steamed vegetables may sound like the best way to go nutritionally, but you’re actually better off eating vegetables with some fat. Many nutrients, like beta carotene, vitamin D, and vitamin K are fat soluble, so they can only pass from our intestine into our blood stream with some fat to carry them across.

41. Continue…  It’s like a nutritional buddy system. So toss those steamed veggies with a flavorful vinaigrette, or sauté or stir-fry them—all of these methods use some fat (which helps maximize absorption) but little if any water (to minimize nutrient loss). They’ll also make your vegetables tastier than plain steamed ones, so you’ll be inspired to eat more.

42. Add Citrus  Vegetables like spinach, broccoli, and kale contain lots of iron, but it’s in a form that’s difficult for our bodies to use, so most of it passes through undigested. Vitamin C, which citrus fruits provide in spades, reacts with iron chemically, changing it into a form that’s more easily absorbed by our bodies. In other words, it makes the iron user-friendly. So go ahead and add a splash of lemon, lime, orange, or grapefruit juice to that stir-fry or sauté.

43. Continue…  The three strategies here are all used in the recipe opposite; it’s a perfect example of how to maximize nutrition in a delicious way. The green beans are briefly steamed instead of boiled. Then they’re sautéed with yellow peppers and shallots in a touch of healthful olive oil until just tender. Fresh spinach is tossed in at the end, and the dish is finished with splash of orange juice. I can’t think of a better way to get the most out of your vegetables.

44. Good to Know!!! Cooking affects how vegetables retain nutrients, but how you prep them matters, too. Here are some tips: Wash before cutting Cutting a vegetable breaks its cell walls, allowing nutrients to escape into any water on contact. By washing uncut vegetables, nutrients stay safely tucked inside their cell walls and won’t be leached into the water. Keep the peel on Many key nutrients are found in or just under the vegetable peel, so leave the peel on whenever possible.

45. Continue…  Cook soon after cutting Nutrients can be destroyed when exposed to light and air. Cook and eat vegetables soon after cutting to keep vitamins and minerals secure in their cells as long as possible. Cut larger, uniform pieces Larger pieces mean fewer cell walls severed and fewer nutrients lost to heat, light, or cooking water. Cutting uniform pieces ensures that everything is done at the same time, eliminating overcooked pieces and loss of nutrients.

47. FUNGI’S MORELS CHANTERELLES

48. FUNGI’S HORNS OF PLENTY CEPS