The Science of Food and Nutrition
While “everyone” agrees that you need to eat from the five food groups:
- Fruit and vegetables
- Carbohydrates (also known as grains or starch)
- Protein (from meat, fish, legumes, nuts)
There isn’t an international consensus on how much of each you need for good nutrition. Nor on how many calories are enough, or too much. Or whether you need to balance each meal, each day, or whether each week is sufficient.
To an extent this is to be expected, because we are all individuals and you can’t generalise across the population of a planet. And science moves slowly on the basis of research, replicating research to confirm the findings, and scholarly debate. Some of it is fact (like Gravity), and some is theory (like String).
Food and Nutrition Scientists
Some experts are nutritionists, and some are dietitians (or dieticians). Depending on where you are, either may or may not be licensed or accredited to provide medical or clinical advice in an personal consultation. Though they may be permitted to offer general nutritional education. In Australia, only Dietitians accredited by the Dietitians Association of Australia may give personal dietary prescriptions.
Added to this, are nutritional schools of thought. They start with adopting core beliefs about things like raw food, whole food, low-fat, low carbohydrate and range up to larger dietary recommendations about Atkins, Palaeolithic or Mediterranean. There are lots of others, this is just a small sample.
National Consensus on Food and Nutrition
I imagine the licensed and accredited kind are bound by the consensus view of their accrediting body, and that these local associations are the ones that have the greatest input to the national guidelines:
- The UK Eatwell Guide that describes what your plate should look like.
- The US Department of Agriculture’s Choose My Plate healthy eating plan.
- Canada’s Food Guide
- The Australian Guide to Healthy Eating
There are of course other national guidelines, but they don’t all come in nice neat one-page pictures.
Alexandria’s Food and Nutrition
So this is the point where I repeat my disclaimer:
Please note that I am not qualified to provide medical advice, and any medical information I provide must be reviewed with your medical team in light of your particular circumstances. This information and my comments represent the opinions I have formed on the basis of information available to me in my jurisdiction, and may not be applicable to you in your place of residence.
My hospital appointed dietitian highlighted the importance of eating to a regular schedule, using an alarm to keep to it if necessary. Oddly enough, I agree the schedule is important because my appetite corresponds more closely to my monthly cycle than my daily routine – I just don’t get hungry. I don’t realise that I need to eat until I start feeling physical symptoms like dizziness and general weakness.
Where it gets difficult, is that the recommended schedule doesn’t match my life. The recommendations are all early; breakfast, snack, lunch, dinner. An early dinner does get digestion well underway before bed, and generally, you need a decent amount of time to generate the hunger you need for a good breakfast that sets you up for the day. But some days I just can’t force myself to eat it.
Perhaps for me, the better route starts with a snack, mid-morning breakfast, mid-afternoon lunch, evening snack and night-time dinner. And that can be achieved within the limits of my drug schedule.
Along with the schedule, comes recommendations for fruit snacks, salad sandwiches for lunch (not reheated leftovers), and smaller dinners with all visible fat removed from the meat before cooking. And, oddly to my mind, a piece of multi-grain bread with every meal rather than say, a serve of tabbouleh with lunch or barley for dinner. Also oddly, the recommendation for balance rather than variety.
Given my lack of hunger, I agree it’s important to try to ensure each of my meals is nutritionally balanced. But I also think it’s important to eat a wide variety of food to ensure a good mix of vitamins and minerals and stuff. I plan my meals anyway, so it’s not that much more work to plan balance and variety as well.
Eat the Right Amount (and no more)
Like the rest of the planet I have problems with portion sizes. Or is that serving sizes? Probably both. The Mayo Clinic helpfully defines a portion as the “amount of food on your plate” and a serving as a “specific amount of food that equals a certain number of calories”. They also offer visual clues about what a serving looks like, though I don’t know how big a hockey puck is. You can also use your hands to get an idea, which is the approach my dietitian suggests.
I’ve done a little weighing here and there, and cooking dishes with a defined number of serves. For me, cooking a weekly variety of dishes that balance the food groups in a defined serving size is easier than trying to calculate quantities of meat, vegetables, and potatoes. And it can be more interesting with a variety of cuisines and techniques across the week as well.
In my last year on dialysis, I could only drink about 500 ml (17 oz) a day. Anything more and the dialysis could not remove it – I had to drink even less the next day to get rid of it. Not to mention the discomfort of carrying around that amount of fluid within my tissues. Post transplant I had to drink about 2 L (about ½ gal) to keep up with my new kidney. I’ve become a little lazy about monitoring my fluid intake, and have recently started tracking it again.
Unfortunately for me, a recommendation on fluid intake depends on who I talk to. Some nephrologists (kidney doctors) at the hospital say there is no need to set a target, others say 2 L. The dietitian didn’t offer a suggestion more detailed than “plenty” of water.
I set a target of 1.5 – 2 L (~ 0.4 – 0.5 gal). When I consistently reach my target, my headaches disappear, the dark circles under my eyes reduce, and I am generally more cheerful. As you would be when the headache you didn’t realise you had (because you are so used to them) disappeared.
My research and experimentation continues. I’m not sure why we all assume we know how to eat properly when we don’t get lessons in it. The things I knew about food and nutrition I learned from my mother who grew up during the war; and she learned how to eat in the context of food shortages and limited rations. We ate a lot of potatoes and cabbage. We didn’t have fruit. These are the basics that have shaped my eating habits for most of my life.
But I think it pays to acknowledge that we don’t know anything and to stay interested in new developments. I recently watched a BBC documentary Britain’s Favourite Foods – Are They Good for You? and learned a couple of new things:
- You can increase the amount of vitamin D in your mushrooms by leaving them in the sun before you eat them.
- Excess carotenoids (the red/orange pigments in plants) are excreted through your skin. Just one pepper (capsicum) and 150 ml (5 oz) of carrot juice each day is enough to provide a detectable healthy glow.
Who knows what we’ll learn next.
As I’ve been researching, I’ve set some general health goals and started publicly monitoring them. It’s pretty embarrassing so far, but I give myself some allowances for my recent ill-health – it’s been three weeks now and I feel mostly better but I have a stamina deficit.