diff --git a/constants.js b/constants.js
index d558257..47528e9 100644
--- a/constants.js
+++ b/constants.js
@@ -260,5 +260,81 @@ const upgrades = {
         "prod-2"
       ]
     },
-  }
+  },
+  "prod-4": {
+    "name": "Quick Metabolism",
+    "desc": "Burn those calories.",
+    "cost": {
+      "food": 5e5
+    },
+    "effect": {
+      "type": "prod-all",
+      "amount": 1.05
+    },
+    "prereqs": {
+      "productivity": {
+        "food": 1e4
+      },
+      "upgrades": [
+        "prod-3"
+      ]
+    },
+  },
+  "prod-5": {
+    "name": "Speedy Metabolism",
+    "desc": "More prey, more power.",
+    "cost": {
+      "food": 5e6
+    },
+    "effect": {
+      "type": "prod-all",
+      "amount": 1.05
+    },
+    "prereqs": {
+      "productivity": {
+        "food": 1e5
+      },
+      "upgrades": [
+        "prod-4"
+      ]
+    },
+  },
+  "prod-6": {
+    "name": "Fast Metabolism",
+    "desc": "You're a furnace.",
+    "cost": {
+      "food": 5e7
+    },
+    "effect": {
+      "type": "prod-all",
+      "amount": 1.05
+    },
+    "prereqs": {
+      "productivity": {
+        "food": 1e6
+      },
+      "upgrades": [
+        "prod-5"
+      ]
+    },
+  },
+  "prod-7": {
+    "name": "Powerful Metabolism",
+    "desc": "Digest them all.",
+    "cost": {
+      "food": 5e8
+    },
+    "effect": {
+      "type": "prod-all",
+      "amount": 1.05
+    },
+    "prereqs": {
+      "productivity": {
+        "food": 1e7
+      },
+      "upgrades": [
+        "prod-6"
+      ]
+    },
+  },
 }
diff --git a/gorge.js b/gorge.js
index ac42f58..6cbfd79 100644
--- a/gorge.js
+++ b/gorge.js
@@ -285,7 +285,7 @@ function upgradeReachable(id) {
       for (let upgrade of reqs) {
         if (!ownedUpgrades[upgrade]) {
           return false;
-        }currentProductivity["food"] = 0;
+        }
       }
     }
   }
@@ -310,8 +310,10 @@ function upgradeAvailable(id) {
       }
     } else if (type == "productivity") {
       console.log(type, reqs);
-      if (currentProductivity < reqs) {
-        return false;
+      for (const [key, value] of Object.entries(reqs)) {
+        if (currentProductivity[key] < value) {
+          return false;
+        }
       }
     }
   }
@@ -418,7 +420,7 @@ function renderPrereqs(prereqs) {
       for (const [id, amount] of Object.entries(prereqs.productivity)) {
         list.push({
           "text": amount + " " + resourceTypes[id].name + "/s",
-          "valid": currentProductivity[id].count >= amount
+          "valid": currentProductivity[id] >= amount
         });
       }
     }