Last Sunday's New York Times looked at some recently released data from the USDA Economic Research Service showing that between 1970 and 2006, the amount of food available to the average American grew by 1.8 pounds of food per week. Among the increases were meat and egg consumption (+0.2 pounds per week), fruits (+0.5 pounds), fats (+0.5 pounds), and refined sweeteners (+0.3 pounds; recall the multi-decade trends in my post about HFCS). Ezra Klein converted the results into a chart that simplifies interpretation a bit. In the end, however, we probably need to look at calories instead of pounds.
The Loss-Adjusted Food Availability dataset contains average calories produced daily per capita for over 200 basic foods, as well as collections of larger food groups. The dataset was constructed by the Economic Research Service by summing the U.S. production, imports, and beginning stocks of a particular commodity and then removing exports, ending stocks, and non-food uses. Then the ERS analysts further adjust the quantity using estimates for spoilage and processing losses. The data are useful as an indicator of trends, but as the USDA's "Limitations of the Data" section says, "...the loss-adjusted data series does not measure actual consumption or the quantities ingested because neither series is based on direct observations of individual intake. Therefore, data are not available by demographic, state, or regional breakdowns, and it is not known where readers can obtain such data."
I have created two charts from the dataset. The first chart shows the average total calorie availability daily per capita between 1970 and 2004 (adjusted for spoilage and processing losses). The increase during that period was more than 500 calories per day, 24% higher than in 1970. if one failed to avoid this temptation and actually ingested 500 additional calories per day it would be tough to prevent it from going to the waistline — it takes 51 minutes of running (5 mph), 51 minutes of swimming, or 108 minutes of walking (3.5 mph) for a 154-pound man to burn 500 calories, according to MyPyramid.gov. (That's the default weight/gender setting, oddly enough — one suspects very few adult American males weigh that little.) Not many people can find the time to exercise that much. And so, obesity rates are stratospheric.
The second chart shows how the calories are distributed across broad categories. Several things jump out at me. The most vigorous leap is the sharp increase in added fat calories since the late 1990s, an increase of almost 150 calories per day — and this follows a nearly 100-calorie increase since 1970. The bulk of the fat increase is from what the USDA calls "salad and cooking oils." While it would be nice to think that most of those oils are extra virgin olive oil eaten in healthy salads or in Mediterranean dishes, I'm guessing that deep-fried and processed foods are the source of most of those calories. Other shifts in the chart are more positive: in the last few years, fat and sugar calorie production have dropped slightly.
The full dataset can be downloaded from the USDA's Economic Research Service as an Excel spreadsheet if you'd like to investigate the availability of wheat flour, margarine, broccoli, beef or any of the other foods in the collection.