Dr Jacqueline Rowarth is an adjunct professor at the University of Lincoln, holds a PhD in soil science (nutrient cycling) and is director of Ravensdown, DairyNZ and Deer Industry NZ.
IDEA: Those of us of a certain age remember this idea from school and the importance of fresh fruits and vegetables in our diet.
Since then we have 5+ per day and food pyramid. But consumption continues to be lower than recommended, and results of a survey published by Research First in October cite price as “usually the reason”.
Stats NZ’s confirmation that we hit a 32-year record with food price inflation of 11.3% for the year ended December supports this rationale.
Compared to December 2021, fruit and vegetable prices increased by 23%. Other food categories have also increased, but not as much as fruits and vegetables.
* Energy needs decrease with age, so what you eat is even more important
* Eight foods to help boost your New Year’s weight loss plan
* Is your ‘healthy’ snack making you fat?
Food is obviously more expensive than before, but the question of actual spending depends on what one is trying to calculate. This could be profit margin, affordability by revenue, or “value for money” for manufacturers or supermarkets.
Second, what is the desired value? Taste? Energy? Vitamins? Protein? Caffeine?
Coffee contains three to four times more caffeine than cola, but black coffee (unsweetened) like diet cola does not contain energy, whereas regular cola contains energy.
A cup of coffee and a glass of cola cost the same, whether at home or in the cafe. If caffeine is what is desired, coffee is of better value.
For most animals, the first requirement after sleep is energy, followed by protein. Theories about protein include the need to obtain enough essential amino acids to meet physiological requirements.
These are obtained from animal protein for the least amount of calories (energy). This is because essential amino acids are in an absorbable form in proportions that meet animal (including human) needs.
The question of how to meet essential nutrient intake was answered by Canterbury-based nutrition scientist Dr Graeme Coles.
He calculated that an adult’s need for essential amino acids, energy, and fiber could be met with six cheddar cheese sandwiches.
The better news is that a cheese sandwich (or six) meets nutritional needs with less environmental impact than other options.
The key is that cheese is made from milk, which is a whole food for baby animals. Unlike meat or soy, all the proteins in milk are accessible.
Also, essential amino acids are in an appropriate protein:calorie ratio. All 3.7 grams of protein can be used in 100 grams of milk and is associated with 42 calories. For interest, 100 g of steak contains 18.4 g of usable protein, which is associated with 187 calories.
In an unsubsidized food delivery system like New Zealand’s, meeting daily essential amino acid requirements is much cheaper using dairy products, especially cheese and butter, than any other approach.
Coles calculated that a sandwich made using 180 g of cheddar cheese, 60 g of butter and 12 slices of whole wheat bread can meet 2,000 calories, while also providing enough dietary fiber to meet all essential amino acid requirements and health recommendations. All about $8…
In addition, studies have shown that such a diet also minimizes greenhouse gas emissions.
“A well-managed dairy cow provides the annual essential amino acid needs of about 17 adults and the energy needs of about 15 adults,” says Coles.
This calculation does not exclude the importance of fruits and vegetables, which are essential for vitamins and contribute to fiber, hence the mantra of 5+ per day.
The New Zealand Health Survey, published in November, shows that half of adults and 70% of children follow the fruit intake guidelines (about two pieces per person per day), but only 10% of adults and 6% of children meet the vegetable intake recommendations. (2.5 to 5.5 servings per day, increases with age/size).
Carrots (33c/100g) are superior to oranges (40c/100g) for vitamins A, E, B3, phosphorus and potassium.
Oranges have it for vitamin C. But oranges also contain much more sugar than carrots.
Adding grated carrots to cheese sandwiches and squeezing lemon juice to delay blackening can be the solution.
Lemons (free in many gardens, but currently $1.05/100g in supermarkets) generally contain less vitamin C than oranges, but are lower in sugar.
Fruits and vegetables are valuable sources of energy, vitamins, minerals and fiber.
There is also growing evidence of additional health benefits from the range of phytonutrients they contain.
Yet in the Research First survey, 64% of respondents said they didn’t meet the 5+ per day recommendation because the prices of fruits and vegetables were too high.
In the food consumed, value, taste and comfort should be considered rather than price.
Journalist and author Michael Pollan’s advice makes sense – eat a variety of foods as close to unprocessed as possible, which can be summed up as: “Eat. Not too much. Mostly plants.”
And don’t forget to add a cheese sandwich.
- Jacqueline Rowarth has been a vegetarian for almost 50 years; Graeme Coles is omnivorous.