t_Articles
t_Articles
March 7,
2005
Nutrition science has identified
almost 50 essential nutrients. Nutrients are chemical substances such as
vitamins, amino acids, minerals and essential fatty acids, that the human body
needs but cannot synthesise itself and so must be included in the diet.
Scientists have also discovered more than 1200 phytochemicals, present in
fruits, vegetables, beans & grains and animal products. Although not essential,
many of these do appear to have positive impact on health and wellness. Of
course, all these healthful nutrients and phytochemicals cannot be found
together in one food or even one group of foods, and relying on a restricted
range of foods carries its own risk, as some nutrients and phytochemcials can be
harmful if consumed too excessively. That's why most dietary guidelines include
advice 'to eat a varied diet' and why there is increasing interest amongst
researchers and health professionals in dietary diversity. Read on to find out
how to ensure your diet is sufficiently varied for maximum health and
wellness...
What Makes a Varied
Diet?
A varied diet will
include a broad selection of foods across the whole range, or most of the
traditional food groups, such as vegetables, fruits, cereals, meat, fish and
dairy products. A varied diet will also include a good mix of foods within each
of these groups - eating two bananas and three carrots each and everyday may
meet the 5 portions of fruit and vegetables per day target, but will not provide
the body with even half the potentially healthful phytochemicals that scientists
have identified in fruit and vegetables.
Research suggests
that an intake of 30 or more different foods per week or more than 12 foods in
one day usually characterizes a diet adequate in essential nutrients. Japan's
dietary guidelines actually includes advice to aim for 30 foodstuffs a day.
To assess daily food
variety, start by grouping similar food together. For examples of food
groupsing see table. Thus, rice congee at breakfast, bread made from a mix of
wheat and rye flours at lunchtime, and buckwheat noodles (sobu) for evening meal
represent four food types during the day. However, grapefruit juice for
breakfast, sweet orange as mid-morning snack and spicy Thai pomelo salad would
be counted as 1 food type for the day.
Variety, Balance,
Moderation are Complementary…
Selecting a variety of foods daily,
fits well with another fundamental piece of nutritional advice, which is 'aim
for balance and moderation'. A balanced diet is a diet which includes enough,
but not too much, of each type of nutrient and food group. For example protein
foods such as red meats, fish, and poultry are rich in iron but poor sources of
calcium; milk and milk products are also high quality protein foods, rich in
calcium but poor sources of iron. So, including both these food groups in a
regular diet is one approach to achieving a balance of both calcium and iron.
Moderation also fits well with a
balanced and varied diet. For example, a moderate fat intake is fundamental to a
healthy diet because some fat (about 15% of total energy content of the diet) is
essential for health, but too much is likely to lead to overweight and heart
disease. On this basis, occasional higher fat foods, will contribute to variety
without compromising health quality of regular diet, especially if types of fats
and oils consumed are varied.
Increasingly,
consumers in Asia enjoy a food supply that includes fresh and processed foods
all year round with little restriction as a result of seasonal variation. It can
be tempting to use this year-round availability to restrict food choices to same
old favorites but a better strategy is to use this increase in choice and
convenience to expand the range of foods and cooking styles enjoyed in the
regular diet.
Tips to Increase Food
Variety
Choose foods that
already provide variety, such as multigrain breads and mueslis.
Serve
accompaniments, like fruit/vegetable salads, sprouted pulses, pickles,
chutneys.
Stir fries,
casseroles, soups and salads are an easy way to increase vegetable variety by
using lots of different ingredients.
Be Adventurous.
Expanding your tastes to enjoy a variety of foods can be fun and exciting.
Aim to regularly
try a fruit or vegetable that is not familiar; for example, when shopping for
groceries shop, aim to pick up a food you don't normally buy.
Enjoy a variety of
national cuisines.
Above all, set
aside time to enjoy meals, drinks and snacks, and to take an interest in the
wide range of foods available and preparation methods.
Advice to Choose a
Varied Diet is International
Overwhelmingly,
"choosing and enjoying a wide variety of foods" is the most consistent message
across dietary guidelines worldwide. Malaysia, Thailand, South Korea, China,
Philippines are just some of the many countries in the Asia region to include
this advice in their official, national guidelines.
Encouraging an adventurous approach
to food and diet is also strongly emphasized in many healthy eating guidelines
for young families in countries all around the world. Regularly offering (but
not forcing) new foods and new preparation methods for foods, to young children
is extremely common and very sound advice for parents who wish to establish
lifelong health eating and lifestyle habits in their children. Of course, many
children develop strong food likes and dislikes and for parents who feel their
children are 'picky eaters' providing and encouraging consumption of a varied
diet can seem an impossible task. In these instances, it's important to avoid
confrontation and instead encourage children to take an interest and pleasure in
food and drink (for example, by involving them in selection, preparation,
shopping etc of foods) and take a long-term approach by continuing to offer new
foods in small amounts alongside favorites and always remembering that most
personal fads will pass over time.
Minute amounts of
phytochemicals such as flavonoids, isothiocyanates, lutein, beta and alpha
carotene appear to be helpful in suppressing cancer development and heart
disease.
The Benefits of
Eating a Variety of Foods
Variety is important
for a number of reasons. It tends to balance the potential positive and negative
interactions among food components, and it also balances the overall
availability of nutrients to the body by providing nutrients in different forms
from different food sources.
A varied diet is also
a more enjoyable and pleasurable diet, adding interest and mystery to the meals
we eat, a talking point over shared meals, and a glimpse into lives, cultures
and customs of people around the world.
Research into exactly
what are the health benefits of a varied diet is still in the early stages, but
published evidence to date, includes:
Variety seems to
protect against onset of Type 2 diabetes, some cancers and cardiovascular
disease.
A study of Type 2
diabetics found dietary diversity reduced risk of macrovascular (large blood
vessel) degenerative change and better blood sugar levels.
Findings from the
US National Health and Nutrition Examination Survey (NHANES) I Epidemiologic
follow up study found better survival rates generally amongst those consuming
food from a greater variety of food groups.
Eating
a variety of nutrient rich, low energy foods, like vegetables and fruit, helps
in weight control.
Evidence from a
limited number of studies indicate that consumption of variety of foods improves
health outcomes such as longevity, reduced incidence and severity of chronic
degenerative illness such as cancer, diabetes and faster recovery from sickness
and injury.
|
FOOD TYPE |
FOODS |
|
Wheat |
Breads made with white or wholegrain wheat flour, wheat noodles,
wheat-based breakfast cereals, cakes, wheat crackers, biscuits |
|
Rice |
White and brown rice, rice cakes, rice porridge, rice noodles |
|
Fungi |
Fresh or dried shitake, oyster mushrooms, ennoki mushrooms, button
mushrooms |
|
Fresh green legumes |
Bush beans, mange-tout, snow peas, garden peas, winged beans |
|
Dried beans |
Adzuki beans, cow peas, chick peas, red beans, red kidney beans, soya
beans, bean curd, tempeh, mung beans |
|
Onions |
Garlic, shallots, leeks, red onions, white onions, spring onions |
|
Flower vegetables |
Cauliflower, green and purple broccoli |
|
Leafy green vegetables |
Kale, lettuce, pak-choi, cabbage, spinach |
|
Gourd vegetables |
Pumpkin, squash, cucumber, marrow, bitter gourd, zucchini |
|
Roots vegetables |
Mooli, carrot, potato, water chestnut, ginger |
|
Stone fruit |
Mango, apricot, plum, prune, olive |
|
Fleshy seeded fruit |
Figs, dates, kiwi, passion fruit |
|
Melons |
All types, e.g. cantaloupe, honeydew, watermelon |
|
Citrus fruit |
Lime, lemon, pomelo, tangerine, orange, grapefruit |
Further Reading
-
Wahlqvist ML et al. Food variety is
associated with less macrovascular disease in those with type II diabetes and
their healthy controls J Am Coll Nutr. 1989 Dec;8(6):515-23.
-
Kant et al. Dietary diversity and
subsequent mortality in the First National Health and Nutrition Examination
Survey Epidemiologic Follow-up Study. Am J Clin Nutr 1993; 57:434-440.
-
Savige et al Food variety as
nutritional therapy Current Therapeutics 1997; March: 57-67
|
