Effect of Consuming Too Few Calories on Nutritional Status

We all know you need to cut back on your caloric intake and increase your exercise if you want to lose weight. However, some people become overzealous in their attempts to lose weight and take their caloric intake too low. In addition to slowing your metabolism, consuming too few calories will short change your body of many important nutrients. This can have short term and long term consequences on your health.

Nutritional needs of our bodies
Our bodies need MANY nutrients in order to promote optimal health. These include macro-nutrients ( protein, carbohydrate and fat) and micronutrients (vitamins and minerals). In addition, certain kind of fats called omega 3 fats, have been shown to have numerous health benefits. We also need antioxidants and phytochemicals to decrease risk of many diseases.  These foods are found in fruits, vegetables and whole grains. It can be overwhelming to make sure you are meeting all your nutritional requirements!

The Food Pyramid
The most important thing you can to do make sure you are meeting your nutritional needs is to consume a variety of foods from all of the food groups.  The Food Pyramid can help you do this. It will give you the recommended number of servings of each food group that you should aim to consume a day.

Short term  effects on nutritional status of consuming too few calories/nutrients
– Decreased energy levels. Like a car needs fuel, your body needs calories in order to function properly. It is highly likely that your energy levels will plummet if you take your calories too low.

– Increased food cravings. Your body will secrete chemicals that will increase cravings for carbs and fat if your caloric intake is too low. So eventually your low calorie diet will backfire as your cravings win!

– Moodiness.  The output of serotonin and dopamine are created by eating carbohydrates and proteins. When you aren’t eating enough of both, or either, you will notice a change in mood. Without the production of those two neurotransmitters, you may notice increased feelings of depression.

Long term effects of consuming too few calories/nutrients
This can cause  can more serious consequences on your body’s health including:
– Increased risk of osteoporosis from inadequate intake of vitamin D and calcium
– Decreased immune system functioning
– Anemia from consuming inadequate iron, B12 or folic acid
–  Heart irregularities, palpitation, or arrhythmia’s. These conditions can be caused by a lack of electrolytes,  namely minerals called sodium and potassium
–  Effects on reproductive system. Loss of menstruation can occur
–  Abnormal artery dilation  For more info, check out this link
–  Increased risk of diseases such as cancer and heart disease. Phytochemicals found in fruits, vegetables and whole grains have been shown to decrease risk of cancer.

So how low should you go?
Ok, so we know that consuming a balanced diet including a variety of foods from all the food groups is important. The question is – how low can you take your caloric intake AND still make sure you are meeting your nutritional needs? This number will depend upon your size, age and activity level … and of course, what foods you are including your eating plan! In general, a woman should not consume fewer than 1200 calories and a man shouldn’t go lower than 1500. Very active or larger people will need even more. Keep in mind that these numbers will be for weight loss for most people.

Nutritional needs of a typical woman.
Check out the Food Pyramid Planner to get your individualized diet plan:

For an example, I calculated what an average 140 pound, 5’4 moderately active woman needs in her diet to be healthy. Here is what I came up with:

– 5.5 ounces of protein rich foods (i.e. meat or beans)  ~ 300 calories
– 3 servings of dairy (preferably low fat or non fat) ~ 250 calories
– 2 cups of fruit ~ 120-240 calories
– 3.5 cups veggies ~ 175 calories
– approximately 6 tsp fat (or 30 grams) ~ 260 calories
– 6 servings of grains a day (one serving = 1 ounce of bread or 1/2 cup cooked grain. (3 of these servings should be whole grains) ~ 480 calories

Think about it, how can you consume all of the above foods if you are eating fewer than 1200 calories? Even if you had the most perfect diet in the world, it would be just about impossible to meet 100% of your nutritional needs if you are consuming fewer than 1200 calories.

So bottom line, if your goal is to lose weight, focus on eating healthy and making nutrient dense choices – as compared to calorie dense. Avoid taking your calories too low. You have nothing to gain by doing this … but a lot to lose (and I don’t mean pounds lost on the scale!)