Just how much fat, protein, carbohydrates, and fiber do you need on a 1200 calorie diet? I’ve been asked this question a number of times and I’ve given responses for individual nutrients. Today I’d like to share with you how to assess what you need for each of the macronutrients (fat, protein, carbohydrates) and fiber all in one place.

The National Academy of Sciences is the government group that has had the responsibility for determining nutrient needs for the American public since 1941. As you might imagine the recommendations of the Academy have changed over time as new information becomes available with ongoing research.

Until the 1990s the recommendations of the Academy were called Recommended Dietary Allowances or RDAs. More recently, the recommendations were updated to be more comprehensive in nature. The new recommendations are now called Dietary Reference Intakes or DRIs.

The DRIs reflect a number of different measures. Of these, the easiest one to work with is the Acceptable Macronutrient Distribution Range. How’s that for a mouthful?

What you will want to remember are the general guidelines for each of the macronutrients:

Protein: 10-35% of total calories
Fat: 20-35% of total calories
Carbohydrates: 45-65% of total calories

The reasons for this breakdown or range of values are complicated. However, no distribution will ensure you are getting enough of each of the various nutrients if you aren’t getting enough total calories in the first place. Please read my article on how to determine a safe and adequate minimum number of calories for you on a low calorie diet. Most women need more than 1200 calories as a minimum! (1200 Calorie Diet: Getting Started!)

O.K., if you have determined that 1200 calories are enough for you while on a low calorie weight loss plan then the values you are looking at equal:

Protein: 10-35% of total calories
120 - 420 calories
30 - 105 grams

Fat: 20-35% of total calories
240 - 420 calories
approximately 27 - 47 grams

Carbohydrates 45- 65% of total calories
540 - 780 calories
135 - 195 grams

(To calculate the grams of protein, fat, and carbohydrates you need to know the potential energy or calories that each gram might provide. In general, each gram of protein and carbohydrate will yield 4 calories. Each gram of fat will yield 9 calories. So just divide (protein or carbohydrate) calories by 4 to determine protein and carbohydrate grams. Divide (fat) calories by 9 to determine the fat grams.)

Your need for fiber is influenced by the number of calories you consume. However to keep things simple I suggest you keep in mind the general guidelines for fiber needs by age and sex. Adult women less than 50 years of age have a recommended fiber intake of 25 grams a day. Women over the age of 50 have a recommended fiber intake of 21 grams a day. If your dietary fiber intake approaches or exceeds the recommended level make sure you are getting plenty of water in your diet.

Please note that these recommendations are for the average person. If you have diabetes or other health challenges you need to follow the advice given to you by your medical doctor or dietician.

I’ve had more questions about being on a 1200 calorie diet and 1500 calorie diet. So this week I will take some time to answer some of those questions.

If you need a nutritionally balanced 1500 or 1200 calorie diet plan please take a look at what I developed and have posted on this site. By following the links for these plans you will also find several menu samples. I hope to add an additional sample menu later today or tomorrow. Please check back.

Here are some of the questions:

1. How many grams of carbohydrate should I have on a 1200 calorie diet?

Not too many years ago, at the beginning of the new millennium, this country was swept by a low carb craze. The craze has passed thankfully, however, many people may have gotten the idea that carbohydrates are not necessary.

Carbohydrates matter for many reasons. One of the most important is that your brain depends primarily on glucose, a carbohydrate, as an energy source. Although most healthy people can adapt to a shortage of carbohydrate and function O.K. for a while, the long-term consequences are not clear.

The National Academy of Sciences has determined the adult brain needs an average minimum 130 grams of carbohydrate a day. However, they recommend that you get 45 to 65% of your total caloric intake from carbohydrates. That corresponds to having from 135 to 195 grams of carbohydrates on 1200 calories a day (or 540 to 780 calories). On higher calorie diets this amount would of course be more.

Why does the Academy recommend more than 130 grams? Quite simply, foods that are a good source of complex carbohydrates (such as whole grain breads and cereals, legumes, fruits, and vegetables) are also an excellent source of vitamins, minerals, fiber, and antioxidants for good health. It is difficult to achieve nutritional balance with 1200 calories so you won’t want to short-change yourself with respect to complex carbohydrates!

If you would like to read more and learn how to determine how many carbohydrates you might need with a higher calorie intake, please read the blog post on this topic at my Chocolate Veggies site.

2. How many grams of fiber do I need on a 1200 calorie diet?

The National Academy of Sciences recommends that women under the age of 50 get 25 grams of fiber in their daily diet. Over the age of 50 the recommendation for women is 21 grams of fiber. If you would like to read more about high fiber and weight loss please read my previous post.

3. Is 1500 calories enough for a woman?

1500 calories may or may not be “enough” for a woman. Calorie needs are dependent on Basal Metabolic Rate (BMR), activity level, and a very small amount for the energy cost of digesting food. These three values are influenced by age, sex, height, and weight.

If you would like to determine the minimum number of calories you might need on a weight loss diet to stay healthy and avoid having your metabolic rate slow down, I recommend you read my previous post on getting started with a 1200 calorie diet. It will help you determine the lowest recommended calorie intake for a given person.