Wednesday, June 09, 2010

How to Eat

Intelligent eating is becoming harder to do every day—mostly because information is uncertain and keeps changing about what is healthful and what the effects of various foods are on our planet. Moreover, human bodies differ significantly. For example, I have diabetes and am healthiest when I almost eliminate carbohydrates.

We are told that the most beneficial thing a person can do for the planet is to stop eating meat. About 18 percent of all anthropogenic GHG emissions are said to originate from domestic animal husbandry. (See the FAO-Report “Livestock’s Long Shadow” .) However, even this conclusion is disputed. Dr. Albrecht Glatzle claims that the correct figure should be zero! He writes:

“1) Except [for] the fossil fuel borne CO2-emissions by the livestock industry (production, processing and commercialization of meat and milk) and except [for] some unique biosphere borne CO2-emissions, associated with land use change (e.g. deforestation), domestic animal husbandry is totally “climate neutral” (using a controversial terminology, only justified under the assumption of any measurable effect of anthropogenic GHG-emissions on global temperature). Why? Because all the CO2 emitted by forage digestion and respiration had previously been captured from the atmosphere through photosynthesis. Therefore, not a single CO2 molecule is added additionally to the atmosphere that had not been there before, recently.

2) This is also true for the methane produced by internal fermentation. Methane derives from organic substances originating from recent photosynthetic processes. And … methane molecules in the air are oxidized to CO2 and water at the end of their residence time in the atmosphere, closing the cycle. As a matter of fact the methane concentration has stabilized or even passed its peak just at the beginning of the new millennium. So obviously, just as much methane is oxidized in the atmosphere as is added to the air per unit of time. The resulting CO2 is available to be re-captured by photosynthesis.” (

Glatzle’s logic is the same as the argument that biofuels are carbon-neutral, since the plants used in their production have already been taking CO2 in before they were harvested. However, some comments following his article revise Glatzle’s conclusions by noting that much fossil fuel is used in producing and processing meat and milk and it does add to the amount of GHG in the atmosphere. (It seems to me that fossil fuels are used to produce and process plant foods too, so perhaps there is no difference.)

I won’t try to resolve this dispute, but will simply adopt the usual assumption that animals vary greatly in their emissions of carbon and that the atmosphere would be better off without livestock and meat-consumption. Nevertheless, I cannot become a vegetarian, so I have to decide what meat I can eat responsibly—both for the sake of my health and for the sake of the planet’s atmosphere. I want to share my thoughts on this and invite you to correct my mistakes. It gets more complicated every day.

We need to start with some comparative figures: How much carbon per kg of various types of food (as CO2 and/or methane) is emitted by producing it. Such figures are hard to come by, but recently a Facebook or Twitter friend sent me some numbers. I can’t vouch for their validity and of course not all foods are shown.

Food/ CO2 Emissions in (g per kg food)
Beef 13,300
Raw sausages 8,000
Ham 4,800
Poultry 3,500
Pork 3,250
Butter 23,800
Hard cheese 8,500
Cream 7,600
Eggs 1,950
Curd 1,950
Farmer cheese 1,950
Margarine 1,350
Yogurt 1,250
Milk 950
Apples 550
Strawberries 300
Brown bread 750
White bread 650

From other sources, I have read that the reason why cows emit so much carbon is that they are ruminants—animals with four stomachs, or actually, four compartments in one stomach. In digesting and re-digesting grass they produce produce a cud and a lot of methane—an estimated 15-20% of the global production of it. Ruminants include cattle, goats, sheep, giraffes, bison, yaks, water buffalo, deer, camels, alpacas, and llamas.

That being so, I resolve to virtually eliminate beef, goat, sheep, bison, and venison from my diet. I have never eaten the other ruminants anyhow. I’ll also switch from butter to olive oil-based margarine. That leaves me with pork, poultry and fish as acceptable meat. (Fish are not shown on this chart, but I don’t think they emit GHG, do they?) Also, I think probably rabbit is okay—though I don’t know where to buy rabbit meat. I’ll also cut back on hard cheese. (Maybe camembert will be okay.) And I would never drink a kg of cream anyhow.

You may remonstrate with me, urging me not to eat meat at all, since it contains saturated fat. But no! A recent study combined the results of 21 previous studies involving 348,000 adults and concluded that we have been misguided for years; saturated fat does not increase your risk of heart disease or stroke. (American Journal of Clinical Nutrition 10; 01:535-46.) In fact, it’s probably more healthful to eat butter than cooking oil, which often contains large amounts of omega-6.

It’s carbohydrates that are dangerous. Sugar is especially harmful, but the other starchy foods get converted to sugar, so we diabetics—and probably you too—should avoid bread, potatoes, rice, and pasta, as well as most desserts. (Channa is an exception; this young garbanzo bean has a very low glycemic index, though one cannot really call it delicious.) But, since all foods are combinations of fats, proteins, or carbohydrates, if you reduce carbs, you have to make up for it with more protein and fat.

I began experimenting and soon found that a high-fat diet reduced my blood sugar to normal levels and automatically reduced my weight a bit too, though I was eating more calories than usual. I haven’t even been taking insulin with meals lately. Of course, it would be preferable to consume mostly high-fat plants than animals, but such things are hard to find. Vegetables and fruits are mainly carbohydrate. Fortunately, olives, avocadoes, and almonds are high in fat, so I’m eating them regularly, along with sashimi salmon several times a week for the Omega-3 content, and a small amount of other vegetables and fruits that are not very high in carbohydrates.

Still, there are other concerns. Nowadays they tell us all to reduce our salt intake. Olives and pickles are packed in brine, so that leaves them out. Moreover, we should worry about nitrates. Although fresh red meat does not cause heart attacks or strokes, bacon, sausage, and cold cuts do so—because of the nitrates they contain.

Hence here are the foods remaining for a reasonable person to consume regularly: avocadoes; nuts; fresh fruits and vegetables (such as carrots, tomatoes, lettuce, and berries); milk; soft cheese; yogurt; olive oil margarine; vinegar; eggs; pork; fish; poultry. That's pretty limited.

Have I missed anything?