At Verywell, we believe there is no one-size-fits-all approach to a healthy lifestyle. Successful eating plans need to be individualized and take the whole person into consideration. Prior to starting a new diet plan, consult with your healthcare provider or a registered dietitian, especially if you have an underlying health condition.
Food combining diets are based on the idea that eating certain foods separately from others can aid in digestion to support weight loss and overall health. There are different variations of food combination diets, but in general, the rules are quite similar. Certain food combinations (protein and grains) are allowed, while others (protein and starch) are forbidden.
Food combining is not a new trend. Its core principles are similar to that of an ancient Ayurvedic diet, which suggests that combining certain foods together such as those that are raw and cooked can slow the digestive process and lead to certain health conditions.
A modern interpretation of food combining emerged during the 1920s. The physician William Howard Hay created the Hay Diet, which separated foods into three groups: acid, alkaline, and neutral. Acid foods (meat, seafood, and other protein-rich foods) and alkaline foods (carbohydrates and starchy foods) were never to be mixed. Dr. Hay believed that his food-combining dietary system would allow the stomach to maintain the correct acid-alkaline balance, thereby improving health and leading to weight loss.
Many food combining advocates believe that certain foods like protein and carbs take different amounts of time to digest and have different effects on the pH level in the digestive tract. These foods should not be consumed together. However, there is no scientific evidence to support these assumptions.
What Experts Say
“The food combining diet forbids eating carbohydrates with protein and requires fruit be eaten alone. Many health experts suggest eating protein with carbohydrates to stabilize blood sugar and provide satiation. This diet promotes distrust of our bodies and foods, and overly complicates eating.”
What Can You Eat?
Those who follow a standard American diet typically pair meat and starch at mealtime. For example, a turkey sandwich for lunch, or eggs, bacon, and toast for breakfast. On a food combining diet, protein and carbohydrates are never eaten together.
In addition to keeping proteins and starches separated, a food combining diet suggests to consume sweet fruit only in moderation and on an empty stomach—a few hours after or 20 minutes before a meal. It is also recommended to drink plenty of water—but not during meals.
What You Need to Know
Proponents believe that when you eat the wrong foods together, digestion is impaired. As a result, undigested food is left in your stomach to ferment and rot. They believe this can lead to illness and/or weight gain, but this is unsupported by scientific evidence.
Food combining rules are strict and regimented. Those who follow these plans are to adhere to the basic principles. Some adjustments can be made to accommodate those with dietary restrictions, such as celiac disease or gluten intolerance. It could prove difficult to follow as a vegetarian, as many plant-based proteins such as legumes and quinoa also contain carbs, which is an off-limits combination.What to Eat
- Meat, fish, poultry, and eggs
- Grains and starchy vegetables, such as squash
- Non-starchy vegetables
- Sour or low-sugar fruit
What Not to Eat
- Sweet fruit (only consume in small amounts)
- Refined sugar
- Processed foods
Never eat protein including eggs, meat, cheese, and seafood with starchy foods like bread, rice, squash, or grains.
Grains and Starchy Vegetables
Consume starchy vegetables and other carb-heavy foods like grains and bread with cooked non-starchy vegetables such as leafy greens only (not proteins).
Avoid sweet fruit as much as possible. Choose sour or low-sugar fruit instead. Eat nuts, seeds, and dried fruit only with raw vegetables.
Certain foods, including dark chocolate, almond milk, egg yolks, cream, coconut water, lemons, butter, and oil, are considered “neutral” and can be eaten in combination with any foods.
Avoid refined sugar and products that include refined sugar. In general, avoid processed foods, as these contain sugars and fats.
Some alcohol can be consumed. Dry red and white wines fall into the protein category and should only be consumed with other proteins. Beer and ale are considered starchy, so they should only be consumed with other starches or cooked vegetables.The Best Alcoholic Drinks to Choose If You’re on a Diet
Pros and Cons
- Emphasizes whole foods
- No carb or calorie counting
- May promote weight loss
- Confusing to follow
- Difficult to categorize
- Not sustainable
- Unsafe for some people
- No scientific evidence
Like all restrictive diets, food combining diets have their benefits and drawbacks. Reviewing the pros and cons can help you make an informed decision about whether you should try this eating plan.
Emphasizes Whole Foods
Following this diet will likely lead to more consumption of whole foods. The protocol bans any foods with added sugars, which eliminates a lot of processed foods (such as sauces, granola bars, and cereals).
It is also easier to keep different types of food separate from each other if they are eaten closer to their natural state. Processed foods are usually a combination of protein, carbohydrates, and different kinds of fat.
No Carb or Calorie Counting
There’s no need for calorie or carb counting, or portion control, which simplifies this otherwise complicated eating plan.
May Promote Weight Loss
A stringent set of rules may help to make more mindful choices about food. When empty calories are eliminated and meals and snacks are carefully planned, it’s possible to consume fewer calories and lose weight. But that may have little to do with food combining.
Any weight loss experienced on this plan is likely the result of a calorie deficit (taking in fewer calories than you’re burning) rather than by combining specific foods.
Confusing to Follow
The diet’s rules are complex and could be hard for some people to follow. That impracticality, along with having to give up certain convenience foods and remembering when it’s OK to drink water and when it’s OK to have fruit, makes this diet difficult to comply with.
Difficult to Categorize
Most foods can’t be categorized as simply acid or alkaline. For example, spinach is alkaline, but it also provides the body with protein (most proteins are considered acidic). Grains like quinoa provide both starchy carbohydrates and protein. It is nearly impossible to neatly categorize foods according to the rules of this plan.
Diets like these are very hard to follow. For that reason, it may not be possible to stick with a food combining diet for the long term. Additionally, any weight loss experienced on this restrictive plan is likely to come back once normal eating habits are resumed.
Unsafe for Some People
Those with certain health conditions should be cautious with food combining. People with diabetes should not consume carbs alone—they also need some protein or fat along with carbs to keep their blood sugar levels from spiking. If you have a chronic health condition, be sure to check with your doctor before attempting this diet.
No Scientific Evidence
Proponents of food combining believe that proteins and carbs are digested at different rates, so it’s harder for the body to process them when they are consumed together. They also suggest that different foods respond to different pH levels in the digestive tract. So if two foods requiring different pH levels are combined, they can’t be digested together. Of course, neither of these beliefs are based on scientific fact.
The body’s digestive system (i.e., saliva in the mouth, acids in the stomach, enzymes in the small intestine, bacteria in the large intestine) works together to digest food and make it usable for the rest of the body. It is capable of performing this function without having to resort to food combining.How Digestive Enzymes in Your Body Break Down the Food You Eat
Is a Food Combining Diet a Healthy Choice For You?
Similar diets base their philosophy on how acid and alkaline foods affect the body. The alkaline diet claims that eating too many “acid-producing” foods changes the normal pH level in the blood, which may cause illness, fatigue, and weight gain. Acid-producing foods (meat, fish, legumes, even whole grains) are not eaten at certain times or in particular combinations. On the macrobiotic diet, foods are used to help balance the body’s yin and yang energies. But in this case, acidic and alkaline foods are eaten together to create that balance.
While elements of both diets have shown to promote weight loss and improve health, research does not indicate that the positive outcomes such as fat loss and reduced inflammation were associated with food combining, specifically.
Contemporary food combining diets are probably most similar to the well-known Suzanne Somers diet, a fad diet that advocates not eating carbs and protein or fat at the same meals. The plan also eliminates sugar to purportedly balance hormones, boost metabolism, and burn fat. Like other food combining diets, “Somersizing” restricts certain foods and is not supported by evidence.
Dietary guidelines set forth by the U.S. Department of Agriculture suggest filling your plate with a combination of protein, grains, fruits or vegetables, and dairy products (if you can tolerate those). While these guidelines don’t specify including every item at every meal, they do suggest it as a goal for a healthy, balanced diet. Of course, this counters the basic premise of food combining.
To achieve your weight loss goal, the USDA recommends cutting your intake by approximately 500 calories per day or aiming for a daily intake of about 1,500 calories. There are no calorie targets on food combining diets—it’s all about what you eat and when and not necessarily how much. This may help some people lose weight, but others may benefit from monitoring their calorie intake. This calculator can help you determine an appropriate calorie goal that’s based on factors such as your age, sex, and activity level.
Due to the restrictive protocol, food combining does not include a variety of nutrient-dense foods at meals and is not aligned with federal guidelines for a well-rounded diet.
While eating more whole foods and reducing calorie intake could improve health and promote weight loss, there is no evidence to show that food combining is an effective strategy.
In fact, only one randomized clinical trial has been conducted since the turn of the 21st century, and researchers were not able to determine that combining foods had any impact on weight loss or reduced body fat.
Though there are no known health risks associated with food combining diets, a strict and regimented diet may lead to an unhealthy obsession with food for some people.
The restrictive nature of this plan may also cause some people to not get enough calories in an effort to avoid combining the “wrong foods.” Not getting enough calories can lead to fatigue and create other health problems such as slowed metabolism.
A Word From Verywell
Food combining (and other eating plans with unique guidelines) are often appealing because they are a departure from traditional diet rules. Sometimes these plans provide interesting routines or a novel approach to weight loss that some people may find intriguing. But the bottom line is that food combining is not a realistic eating plan for the long term.
The strict protocol is likely unnecessary—weight loss and better health can be achieved with a balanced diet that includes all the major food groups combined with regular exercise. If you would like to lose weight, you may want to consult a registered dietitian or your healthcare provider to set goals and monitor your progress. You’re much more likely to see results that last if you follow plans that are rooted in science.
Remember, following a long-term or short-term diet may not be necessary for you and many diets out there simply don’t work, especially long-term. While we do not endorse fad diet trends or unsustainable weight loss methods, we present the facts so you can make an informed decision that works best for your nutritional needs, genetic blueprint, budget, and goals.
If your goal is weight loss, remember that losing weight isn’t necessarily the same as being your healthiest self, and there are many other ways to pursue health. Exercise, sleep, and other lifestyle factors also play a major role in your overall health. The best diet is always the one that is balanced and fits your lifestyle.