One of the first government graphics on recommended food groups was published by the Swedish government in 1972. It featured a seven slice pizza-shape, with three separate groups for vegetables (leafy/green/yellow, citrus fruit/tomatoes/raw cabbage, and potatoes/other fruit), a milk/cheese/ice cream group, and a group just for butter/fortified margarine! The Swedes found this confusing, and two years later, the Kooperativa Förbundet (a retail chain) released the first food pyramid to represent better how much of each food group should be eaten, like not eating butter in equal portions to whole grains. The Swedish government never accepted the commercial version1.
What kinds of foods to fill your plate is critical for determining how healthy your diet is. Unfortunately, in the plans presented by governments and companies, science often comes second to the preferences of their sponsors and stakeholders. This is why the US Department of Agriculture recommendations feature milk as its own category, despite questionable health impacts and other easy protein substitutes.
In 2017, the American Journal of Clinical Nutrition (AJCN)2 released a systematic review and meta-analysis of the studies that have been published on different food groups (they didn’t provide butter/margarine as its own food group, though) and how each affects all-cause mortality. I consider all-cause mortality the gold standard for whether something is healthy. The body is complex, and it can be easy when working with food components to show a particular ingredient is good or bad for you. These studies about this chemical being good or bad are often disproven later when they extract the chemical and do a randomized, controlled trial. In comparison, death as an endpoint is pretty unambiguously bad. I’m pretty sure that later studies will not find it is good for you. 😉
The AJCN study provides a solid baseline of how each food group affects your health. I talked about how nuts are good for you in my previous post, but only up to 20 grams. Many other healthy foods also show limits to their benefits. Vegetables provide longevity benefits up to 300 g per day. After this, no additional help. Fruits improve health up to 250 g per day, with no extra credit for eating more.
Several foods show benefits that keep growing through the testing range, so we don’t know the “maximum beneficial dose” because not enough people eat enough to show statistical results for them. Beans (150+ g/day), whole grains(150+ g/day), and fish (100+ g/day) all show this pattern.
Other foods increase all-cause mortality and have no upper limit to how much harm they can do from this study. Red meat (bad), processed meat (even worse), eggs, and sugar-sweetened beverages show this pattern.
Milk and dairy have their own category. No harm (or benefit) up to 750 ml/day, but continued increased mortality after that point.
Refined grains and poultry are base neutral. No increase or decrease in all-cause mortality was shown at any amount.
I haven’t made any pyramids yet or plate diagrams to show how to get this amount of food, but I have made a calculator based on US actuarial tables to calculate how your diet affects your effective true age. Give it a try!