Although fat has been vilified (at least in the U.S. and other Western countries) since the 1960s, in recent years people have been coming back around to the reality that fat is a necessary macronutrient in the human diet.
At the same time, people are looking to legumes to provide basic nutrition in their diets, and so they may wonder if legumes are a good source of healthy fat.
Healthy fats have a huge role in the human diet.
We need them for hormone health, fat-soluble vitamin absorption, hair and nail health, cell signaling and repair, and many other physiological processes.
Fat is also calorically-dense, so if you over-consume it you will gain weight, even if it is a so-called “healthy fat.” Legumes are not typically high in fat, except for peanuts and peanut butter.
Are Legumes High in Fat?
The majority of legumes are very low in fat.
With beans and lentils, for example, the bulk of the calories come from carbohydrates, some from protein, and a minuscule amount comes from fat.
The only commonly eaten legume that is high in fat is the peanut.
The fat content in peanuts is composed of more than 50% monounsaturated fat, which is commonly thought of as a “healthy fat.”
Soybeans are moderately high in fat, with about 44% of its calories coming from fat.
See the table below for a comparison between five commonly eaten types of legumes:
|Type of legume||Grams of fat in one cup|
Notice that black beans, lentils, and chickpeas are all very low in fat.
The caloric content in these foods come mainly from carbohydrates.
For example, 76% of the calories in a cup of cooked black beans comes from carbs.
They also contain some amount of protein (I.e., there are 14.2 grams of protein in a cup of cooked black beans).
Soybeans, on the other hand, have a more balanced nutritional composition.
1 cup of cooked soybeans contains 296 calories. 37% of these calories comes from protein, 20% from carbs, and 44% from fat.
The difference in the nutritional composition of peanuts is even more pronounced. 1 cup of dry roasted peanuts has a whopping 857 calories. 14% of these calories come from protein, 15% from carbs, and 71% from fat.
Since fat contains 9 calories per gram, this explains why the calorie content of peanuts is so much higher than low-fat legumes.
According to the NCCDB database, more than half of the fat content in peanuts is monounsaturated, with the rest being polyunsaturated or saturated. Monounsaturated fats are widely accepted as “healthy” fats, due to their generally positive effect on cardiovascular disease risk markers like LDL and triglycerides.
However, it is important to keep in mind that even healthy fats are high calorie foods.
If you are looking to lose weight, you will need to reduce caloric intake.
This means paying attention to your portion size whenever you eat peanuts or peanut butter, or other high fat and high carb foods.
The fact that certain fats are labeled as “healthy” does not mean you can eat them with reckless abandon and still hope to lose weight!
Benefits of eating beans and rice together
Beans and rice make a cheap, convenient, and delicious dish that is often paired together in many cultures’ cuisines.
Increasing the amount of beans in the dish will boost the nutritional content, as rice is much lower in nutrients (other than carbohydrates).
Beans and rice also pair well with other nutritious whole foods such as meat, dairy products, and fresh vegetables and herbs.
One of the biggest advantages of beans and rice is that they are relatively cheap — this is why they feed much of the world.
Eating rice and beans together is a long-standing tradition in many cultures, so for many people it is almost in their DNA to crave rice and beans.
Rice and beans, often paired with foods like hot tortillas, sour cream and cheese, and freshly made pico de gallo, are found in the center of many tables around which families and friends come together to share meals around the world.
This is an element of food and nutrition that we often don’t appreciate in our modern world, with our sometimes overly reductionist thinking and tendency to reduce the benefits of food to its macronutrient content.
Food is much more than a compilation of vitamins, minerals, and protein.
It is something that bonds us with our families, friends, and cultures — and beans and rice dishes have served that role for centuries.
From a nutritional perspective, beans are the more nutritionally-rich food, compared with rice.
With regards to macronutrients, rice is basically pure carbohydrate, while beans contain protein in addition to carbs. See the table below:
|Type of food||Total calories in 0.5 cup||Protein (grams)||Carbs (grams)||Fat (grams)|
|White rice (steamed)||103||2.1||22.3||0.2|
|Black beans (canned and drained)||120||7.1||22.4||0.5|
Neither beans nor rice are particularly rich in micronutrients, but beans are the more nutritious of the two.
White rice has small amounts of B vitamins and some minerals (such as manganese), but black beans have significantly more folate and a higher level of some minerals (like phosphorus).
Furthermore, beans have more fiber and thus slow the release of carbs into the bloodstream, which may enhance blood sugar control — a key factor to consider when consuming a meal that is high in carbs, as a meal of rice and beans would be.
Can I live on beans and rice?
You may be able to live on only beans and rice for a period of time, but you would not thrive on a diet like this.
Beans and rice would provide sufficient calories, provided you eat enough of them, but they would not provide a balanced or adequate level of protein, vitamins and minerals, or essential fats.
The primary macronutrient provided by beans and rice is carbohydrates.
Carbs are useful as an energy source for humans, provided you have well-functioning hormones that can utilize them efficiently.
But carbs are not essential to the human diet in the same way that protein and fats are.
We need protein to maintain, repair, and build basically every structure in the human body.
We need fats to absorb fat-soluble vitamins, create and maintain cells, and maintain brain health.
But carbs are replaceable, at least from a physiological perspective — they are not essential.
Neither beans nor rice provide the basic amount of essential fatty acids that are necessary to maintain health, so they fall short in this regard if you are relying on them as your only source of nutrition.
Beans do provide some protein, but you would need to make sure you’re eating at least 2-3 times more beans than rice in order to ensure that you’re getting even the bare minimum of protein necessary to avoid disease.
Incidentally, many poor people rely on beans and rice as staple foods because they are cheap and easy to come by in many parts of the world.
But beans are usually the more expensive of the two foods, so what many people do is eat more rice and less beans.
This is unfortunate, because it significantly dilutes the already paltry amounts of nutrition present in the meal.
How long can you survive on beans?
The amount of calories needed to survive varies from person to person and depends on many things — basal metabolic rate (BMR), activity level, current weight, and the amount of fat stored in the body.
The length of time you could survive only eating beans would likewise vary widely from person to person.
It’s impossible to give a hard and fast rule for how long you could survive eating only beans.
In fact, the world record for longest time spent without food was 382 days, so if you have a significant amount of fat stored in your body, you could theoretically survive a very long time eating nothing, or eating only beans (it’s important to note that the record-breaking fast was carried out under medical supervision, and the subject also consumed vitamins and minerals during his fast).
However, it’s important to distinguish between thriving and merely surviving.
If you are fortunate enough to have the wealth to be able to purchase, hunt, gather, or otherwise obtain food, your goal should be to thrive and not to merely survive.
If you eat only beans for more than a few days, you will not thrive.
Can you survive eating only one food?
You can survive only eating one food for a time.
How long you would survive would depend on the type and amount of food you’re eating, as well as the basic amount of calories that you personally need in order to avoid malnutrition.
This, in turn, depends on your personal basal metabolic rate, activity level, current weight, and amount of fat stored in your body that can be used as energy.
If I had to choose only one type of food to eat for the rest of my life, I would choose beef.
There is a growing number of people who actually choose to eat this way and appear to be not only surviving but thriving, even after many years of eating only beef on a daily basis.
As mentioned above, the essential macronutrients for humans are protein and fats — both available in abundance in beef.
Beef is also rich in B vitamins, choline, and many minerals like phosphorus, potassium, and zinc.
It also contains essential fatty acids, including omega-3 fats.
The nutrients present in beef are also highly bioavailable and therefore used efficiently in the body.
Beef is also easy to digest for the typical person.
Researchers at Tel Aviv University in Israel collected multiple lines of evidence from different fields of study and used this to reconstruct the diet of Stone Age humans.
Based on this reconstruction, the researchers surmised that Stone Age humans lived on mostly meat (likely the meat of large animals such as mammoths) and probably little else.
Personally, if I were forced to restrict my diet to only one food for the rest of my life, I think I would have the best chance of surviving if I mirrored the diet of our Stone Age ancestors.
Granted, beef is lower in quite a few micronutrients — namely, vitamins A and C, as well as some minerals — and I am unsure how long it would take for nutrient deficiencies to start having detrimental effects on my health.
I may not thrive on a diet of only a single food, but if I had no other choice I believe that meat of a ruminant animal (i.e., beef) would be my best chance at surviving, and maybe even thriving.
I’m Chris Watson & the Founder of EatForLonger.com. I’m a food and wellbeing enthusiast researching and sharing foodstuffs and simple food-based concepts, such as fasting and clean eating.
I hope it inspires you to make tiny changes to what you eat and when you eat while optimizing your healthspan and all-around well-being.
Read more About Me here.