Evidence on global food and grain stocks around 2020 shows that the world had far more than 30 days of caloric supply in storage.

• FAO cereal stock data (2019/20–2020/21). FAO’s Cereal Supply and Demand Brief projected world cereal stocks at about 863 million tonnes for 2019/20, with a global cereal stock‑to‑use ratio of ~31%, characterized as a “comfortable” supply situation.(farms.com) For 2020/21, FAO projected cereal stocks of ~866 million tonnes and a stock‑to‑use ratio of 30.7%.(feedstuffs.com)
• Converting stock‑to‑use ratios to days of consumption. IFPRI and other analysts routinely translate stock‑to‑use ratios into “days of use” by multiplying the ratio by 365 (e.g., SUR × 365).(ifpri.org) A 30–31% stock‑to‑use ratio therefore implies on the order of 110–115 days of global cereal consumption in storage, not 30 days.
• Historical “tight” years are still well above 30 days. Analyses of earlier tight markets found world grain stocks at 57 days of consumption in 2006(search.issuelab.org) and about 68 days in 2012(countercurrents.org)—levels widely described as dangerously low, yet still more than double Friedberg’s 30‑day figure.

Friedberg’s statement—“The world lives on a 30 day food supply. So if you stop food production today, there would only be 30 days of food for the whole world to eat based on our calorie consumption per day”—rests on the factual claim that existing global food stocks equaled roughly 30 days of caloric consumption at that time. Contemporary FAO and related data instead show roughly 3–4 months of cereal consumption in storage, even before counting non‑cereal foods and retail/household stocks.

While the hypothetical “if you stopped production today” scenario was never literally tested, the empirical prerequisite of his prediction (only ~30 days of food in stock) is inconsistent with the best available global stock data. On that basis, the prediction is wrong.