The gallon of milk a day (GOMAD) diet is exactly what it sounds like: a regimen where you drink a gallon of whole milk daily. This is in addition to your regular intake of food. This “diet” isn’t a weight loss plan, but rather a semipopular “bulking strategy” for weightlifters looking to put on muscle mass in a short amount of time.

The idea is to drink a gallon of whole milk every day until your goal weight is reached. This usually takes two to eight weeks.

Overly flattering GOMAD testimonials are plentiful on the internet. But is it necessary, safe, and worth some of the unpleasant side effects to try? Here’s a look at the pros and cons.

The whole picture on whole milk

A gallon of whole milk provides roughly:

  • 2,400 calories
  • 128 grams of fat
  • 176 grams of carbohydrates
  • 128 grams of protein

It’s not surprising that GOMAD “works” as far as helping individuals put on weight quickly. Liquid calories are less satiating than ones from solid food. That’s why it’s easier to drink an additional 2,400 calories than to eat them. The absence of fiber in milk (fiber takes up real estate in our stomach, which is why higher fiber diets are associated with weight loss) makes it easier to gulp down an additional 2,400 calories than chew them.

Consider this theoretical “daily supplement” of 2,400 calories from solid food. You’d need to eat:

  • 2 avocados (644 calories)
  • 4 cups of rice (618 calories)
  • 1 cup of nuts (529 calories)
  • 12 ounces of chicken (420 calories)

It’s no wonder that gulping down 16 cups of milk seems like a more attractive and less time-consuming option.

Pros of the GOMAD diet

  • Drinking a gallon of milk might be less time-consuming than eating the equivalent 2,400 calories.
  • You will reach your goal weight quickly on this diet.
  • This diet may work well for weightlifters or bodybuilders.

Is GOMAD safe?

A gallon of milk provides certain nutrients in very high amounts. But that’s not always a good thing. Consider the 1,680 milligrams of sodium, which is 73 percent of the daily recommended limit. That’s also before you calculate all the other foods and beverages you’d consume in that same day.

A gallon of milk also adds up to 73 grams of saturated fat. There’s no question that getting that much saturated fat (almost 400 percent of the daily recommended limit) from milk supplementation alone is not healthy.

Despite claims from GOMAD enthusiasts that saturated fat aids testosterone production, the same is also true of monounsaturated fats. These are found in healthful foods, including:

  • avocados
  • pecans
  • almonds
  • peanuts
  • olives

Studies have found that lowered testosterone production is only a concern with long-term diets where fat contributes fewer than 20 percent of total calories. The average American adult male takes in 2,512 calories a day. Of these calories, 837, or 33 percent, come from fat. There isn’t any data to suggest that adult American men are not producing enough testosterone because of a lack of dietary fat.

Calcium is one nutrient most Americans don’t get enough of. A gallon of milk a day delivers calcium in plentiful amounts (4,400 milligrams, well surpassing the daily recommendation of 1,000 milligrams). But such a high contribution of the mineral can be harmful. The Food and Nutrition Board of the Institute of Medicine recommends not surpassing 2,500 milligrams of calcium a day. This is because of concerns about impaired kidney function and an increased risk of kidney stones.

Cons of the GOMAD diet

  • GOMAD can result in uncomfortable gastrointestinal symptoms such as bloating, nausea, and diarrhea.
  • You have to carry around milk with you throughout the day because it’s difficult to consume this much milk at once.
  • A gallon of milk contains around 1,680 milligrams of sodium and 73 grams of saturated fat, high above the daily recommended amounts.

Caution: Gastrointestinal distress ahead

Extremely high amounts of saturated fat and calcium are not healthy, but you could argue that drinking a gallon of whole milk a day for a short period of time is no reason to raise red flags.

Fair enough. But GOMAD can result in uncomfortable gastrointestinal symptoms that can show up as early as day one. Among them are bloating, nausea, and diarrhea. These symptoms are even felt by individuals who don’t report lactose intolerance or an allergy to milk protein.

A look through fitness and bodybuilding messaging boards reveals many posts from GOMAD “newbies” asking if abdominal pain, frequent bathroom trips, and distended stomachs are normal.

Discomfort aside, this also demonstrates how GOMAD can interfere with daily life. Be prepared to carry milk with you throughout the day, as this diet requires milk consumption frequently. It’s much easier to split 16 cups of milk throughout the day than to try to pound it all at once.

Next steps

Adding a gallon of milk to your daily diet certainly addresses the caloric excess needed to gain weight and support muscle building (if one engages in muscle building physical activity, of course). But that doesn’t make GOMAD a good idea.

While some of the weight put on as a result of GOMAD will be muscle mass, a significant amount will also be adipose tissue. Whatever calories are leftover from supporting muscle growth are deposited as fat.

By comparison, a more carefully planned and less extreme diet over a longer period of time can help with a goal of gaining weight, with most of that coming from increased muscle mass. Since GOMAD is unsustainable in the long term, whatever gains are accomplished eventually end up dwindling, too.

This is simply the opposite of crash dieting. The end result may be weight gain rather than weight loss, but GOMAD raises the same red flags that starvation diets do: chasing a specific body image that’s often unattainable, and unpleasant side effects that are supposed to be ignored or pushed through. These actions are not about building healthful habits for the long term.