Health Benefits of Low Calorie versus Low Carbohydrate

by Tanya Zilberter, PhD

How exactly calorie restriction works to prolong life is unknown. One of working hypotheses is that dietary restriction alters some, maybe many, of the nervous and hormonal functions that regulate the body fuel use.

Low Calorie and Low Carb

This article continues the topic: Calorie Restriction and Life Span

One of working hypotheses is that dietary restriction alters some, maybe many, of the nervous and hormonal functions that regulate the body fuel use. Dr. Masoro's findings on carbohydrate metabolism are in accordance with this view.

"Diet-restricted rats can use carbohydrate fuel as effectively as "ad libitum" fed rats, while maintaining lower plasma glucose and insulin level. Maintenance of these low levels may protect against [any] long-term damaging actions of these substances. Dietary restriction also protects against oxidative damage and, of course, oxidative damage is probably an inevitable component of fuel use." (Journals of Gerontology, Series A, Biological Sciences & Medical Sciences. 50(3):B148-54, May 1995)

However, the dietary source of carbohydrate has not been widely investigated in this respect. Researchers in Department of Nutrition, University of California, Davis, hypothesized that the dietary carbohydrate source may affect the life span of rats independent of caloric restriction, and found that incorporating refined sugars into 60 percent of a calorie-restrictive diet (instead of complex carbohydrates) removed all beneficial effects!

"Our data support the hypothesis that the dietary source of carbohydrate, i.e., sucrose versus cornstarch, can significantly affect [the] life span independently of caloric intake." (Journals of Gerontology, Series A, Biological Sciences & Medical Sciences. 50A(1):B48-53, 1995)

It is often asked by eager low carb dieters: "What if I restrict calories as well as carbohydrates? Will I be losing weight faster?"

The answer is: If you wish to restrict calories, that's fine. However, you must keep it in your mind that in this case you will have no advantage using "low carb low calorie" diet comparing with low calorie balanced diet. At least not during the first 10 days on a low carb diet.

Clinical studies conducted on healthy volunteers eating same calorie diets, revealed that while "low calorie low carb" ketogenic diet caused weight loss about 500 gram (roughly one pound) a day, 300 grams were due to pure water. Balanced dieters lost modest 300 gram but only 120 gram of water.

Amazingly, fat loss was roughly was the same 180 grams a day on both diets and protein loss was even slightly higher on ketogenic low calorie diet - 3.8 grams a day versus 3.4 grams on balanced low calorie diet.

What happens on a long run? It was shown that after 8 weeks on ketogenic diet, dieters dropped more weight, serum triglycerides, cholesterol, and insulin production than dieters given low calorie diet.

The bottom line is:
1) The beauty of low carb diets is that you don't have to reduce or even count calories.
2) "Low carb low calorie" diets don't have any advantages comparing with just low calorie balanced diets.
3) Low carb diets work best on a long run.


Journal of Clinical Investigation, 58(3): 722-30 1976
Bulletin of Medical Infant Hospital Mex. 37(4): 667-77 1980
Annals of Internal Medicine, 63(4): 604-12 1965
Acta Paediatrica Hungarian Academy of Science, 20(1):99-103 1979


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What low carb plan have you tried the most?
Atkins Diet
South Beach Diet
No White Diet - no white flour, potatoes, white rice
No sugars, high sugar fruit, starchy vegetables
I created my own low carb plan
Total votes: 1076

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