Milk can certainly be a part of your diet. It’s high in bone-building minerals, offers muscle-building protein and has plenty of B vitamins to keep your energy up. But just because milk has healthy components doesn’t mean you can drink as much as you want. A gallon of milk a day is excessive and can cause some unpleasant side effects.
Milk is rich is calcium and the vitamin D added to milk helps your body absorb calcium. While calcium can be beneficial for bone health, it can be devastating to your kidneys in large volumes. High calcium intake sometimes leads to milk-alkali syndrome, a condition in which your body’s acid-alkaline balance shifts, becoming more alkaline. Calcium deposits can form in your kidneys, causing kidney stones and minimizing kidney function as tissues harden. Avoid consuming more than 2,500 milligrams of calcium daily from food and supplements, which is a bit more than double the recommendation for most adults, the Food and Nutrition Board of the Institute of Medicine advises. A gallon of whole milk has 4,400 milligrams of calcium, while skim milk has 5,060 milligrams.
Too many calories in your diet is likely to lead to weight gain over time. Gaining just 1 pound could result by consuming an extra 3,500 calories. A gallon of nonfat milk has around 1,450 calories, while a gallon of whole milk has 2,380 calories. So if you’re regularly drinking a gallon of milk a day, those calories quickly add up. Your weight might go up a pound in as little as three days by drinking a gallon of nonfat milk daily. If you drink whole milk, you may gain a pound in less than two days.
Milk, even nonfat milk, contains saturated fat and cholesterol. When combined, saturated fat and dietary cholesterol are tied to higher levels of low-density lipoprotein, or LDL. This is the “bad” cholesterol known for its artery-clogging capabilities. When your LDL is up, so is your risk of developing cardiovascular disease. Limit your saturated fat intake to fewer than 10 percent of your calories, as stated in the Dietary Guidelines for Americans 2010. Aim for a maximum of 22 grams of saturated fat daily for a 2,000-calorie diet. Keep your dietary cholesterol intake to less than 300 milligrams. To put it into perspective, a full gallon of whole milk has about 73 grams of saturated fat and 390 milligrams of cholesterol. The same amount of nonfat milk contains nearly 6.5 grams of saturated fat and almost 80 milligrams of cholesterol.
Other Cardiovascular Concerns
High sodium intake, above the maximum allowance of 2,300 milligrams daily, can elevate your blood pressure. Cells swell and retain fluid when too much sodium is present. When tissues swell up, your heart has to work more to circulate blood, resulting in increased blood pressure. A glass or two of milk adds some sodium to your diet. However, if you drink an entire gallon, you’ll get 1,680 milligrams of sodium from whole milk -- almost 2,080 milligrams from a gallon of nonfat milk. These levels take up roughly 75 to 90 percent of your daily sodium allowance, respectively.