The commonly held idea is that obesity or excess fat accumulation is simply to due to excess energy consumption. Obesity is seen as a result of too much food consumption, gluttony, and too little activity. The solution is to consume less calories and exercise more to burn more energy. Eat less, move move, lose fat. Does it always work? Unfortunately, no.
I have questioned the negative net energy balance ideology since becoming a health professional as I have personally witnessed both men and women who restrict their calories in the efforts to reduce fat stores yet are unsuccessful at doing so. I am certain my clientele is not alone in this problem. So this means that factors other than calories in, calories out are dictating whether fat tissue stays or goes. An article written by Dr. Benjamin Caballero that was published in the New England Journal of Medicine in April of 2005 brings this scenario to light on a larger scale. Dr. Caballero is director of the Center for Human Nutrition and a professor of international health at the Bloomberg School of Public Health, Johns Hopkins University.
The article, entitled “A Nutrition Paradox – Underweight and Obesity in Developing Countries“, describes the co-existence of both the obese and underweight within the same poor population in the slums of Sao Paulo, Brazil. There are a few portions of Dr. Caballero’s writing that are interesting. I will provide those excerpts and comment on them.
“A few years ago, I was visiting a primary care clinic in the slums of São Paulo. The waiting room was full of mothers with thin, stunted young children, exhibiting the typical signs of chronic undernutrition. Their appearance, sadly, would surprise few who visit poor urban areas in the developing world. What might come as a surprise is that many of the mothers holding those undernourished infants were themselves overweight.”
Here we see the co-existence of obese mothers carrying underweight, malnourished children. Does this mean that the mothers are gorging on food while starving their own child who is undernourished? If the energy in, energy out crowd were indeed correct, that would be an explanation to validate how this possibly could occur. Understanding the pre-programmed motherly instinct that women have, we can conclude that these mothers are not intentionally starving their own children so they could consume excess calories. Something else is in action creating obese mothers and underweight children.
“The reasons are not completely clear, but it is obvious that in poor countries, the dietary energy intake of the poorest people may be limited by the scarcity of food, and the high energy demands of manual labor and daily-survival activities make it difficult for people to achieve a net positive energy balance and therefore to gain weight.”
Despite scarcity of food and a high activity level due to manual labor and survival activities, individuals are still obese. This scenario is what is commonly suggested for weight loss by many – less energy intake, high activity level. Eat less, move more.
Cabellero remarks that because of these factors it would make it diffcult for these individuals to have a “net positive energy balance” that is usually associated with weight gain. This indicates that despite a net negative energy balance, fat accumulation and obesity still resulted in this population of Brazilians.
“Factors other than diet and lifestyle also link early undernutrition with overweight in adulthood. The hypothesis of “fetal origins of disease,” which is supported by a number of observational epidemiologic studies, postulates that early (intrauterine or early postnatal) undernutrition causes an irreversible differentiation of metabolic systems, which may, in turn, increase the risks of certain chronic diseases in adulthood. For example, a fetus of an undernourished mother will respond to a reduced energy supply by switching on genes that optimize energy conservation. This survival strategy causes a permanent differentiation of regulatory systems that result in an excess accumulation of energy (and consequently of body fat) when the adult is exposed to an unrestricted dietary energy supply. Because intrauterine growth retardation and low birth weight are common in developing countries, this mechanism may result in the establishment of a population in which many adults are particularly susceptible to becoming obese.”
Cabellero brings great insight to the discussion namely that early (in womb, postnatal) undernutrition can lead to irreversible modification to the metabolism which may increase the likelihood of chronic disease and obesity during adulthood. Individuals born into circumstances where the mother is malnourished and/or food is scarce respond to reduced energy consumption by switching on genes that “optimize energy conversation.” This switch to turn on obesity genes may be the body’s own built in survival mechanism to enter a world where food is scarce. During times when food is not so scarce, these individuals are far more prone to accumulating excess fat stores and put themselves at risk for obesity and the diseases associated with it. Because many children in impoverished areas are born to undernourished mothers and in environments where food is scarce, populations of children may be born with this energy conserving gene flipped permanently in the on position.
Dr. Cabellero’s observations of the people of Sao Paulo illustrates that the body isn’t a calorimeter, and the complexity of the body and its built in survival mechanisms are vast and not yet fully understood. We can conclude that fat loss is more than just creating a negative energy balance for some individuals.
Those that have a properly working metabolism may indeed benefit from the calories in, calories out ideology. However, those that have some metabolic system damage (or other dysfunction) that existed at birth or came about during childhood or adulthood must not become frustrated when restricting energy intake and increasing energy consumption doesn’t result in the desired fat loss. One should then look for blocking factors in such a case to determine what steps need to be taken to improve the likelihood success when reduction in excess fat stores. Every case is different; it’s up to your health professional and yourself to figure out the answers to your puzzle.