Although weight gain is essentially caused by an imbalance between energy input and energy output, there are several factors that predispose individuals to obesity.
Genetics, fat absorption, metabolic rate and appetite all influence weight gain.
Several spices, including chilies, garlic, ginger and fenugreek , help to prevent and combat obesity. They act by suppressing the appetite, reducing fat absorption and fat deposition, and increasing the metabolic “burning off” of fat.

Fat Metabolism and the Causes of Obesity
Fat deposition is a defensive mechanism that enables the storage of energy when food is abundant, thereby increasing the chances of survival during times of food scarcity and famine. In earlier times those individuals who were efficient at storing fat were more likely to survive food shortages, and fat storage was especially valuable in pregnant and lactating women due to their higher than normal energy requirements. Unfortunately, during modern times of plenty we still retain this innate capacity to store fat and what was once an advantage for the efficient energy accumulators has now become a health risk for them.

Viewed simplistically, obesity is caused by too much energy intake, in the form of food, and not enough energy output, in the form of basic metabolic processes and exercise. However, the reasons that so many of us become overweight or obese are a little more complex than this straightforward equation suggests. Although a sedentary lifestyle and the availability of cheap, high-energy carbohydrate and fat-laden foods are the principal causes of obesity, there are sometimes other aggravating factors to consider.

These are diverse and include a genetic predisposition; lifestyle-related factors such as stress and sleep deprivation; psychological problems that manifest themselves as eating disorders; underlying illness; certain medications; a diet dominated by high glycemic index foods; and habitual dieting with its attendant weight cycling. It has been suggested recently that certain virus infections can increase a tendency to put on weight.

In many cases these factors work by interfering with our appetite control mechanisms, which are partially responsible for the maintenance of normal weight.

Appetite Control
The failure of appetite control is often directly responsible for obesity and can exacerbate and entrench the condition once it has developed. Satiety control mechanisms may also be dampened a consequence of obesity which has been caused by other factors. A number of mechanisms are involved in this complex regulatory system, and a malfunction of any one of these may result in the consumption of excess food. 

The senses of smell and taste are two of the most important of the appetite control mechanisms. When we smell or eat food, receptors in the nose are stimulated by food odor molecules and convey these signals to the satiety center in the brain. By monitoring the intensity of these signals, the satiety center is able to gauge when we have had enough to eat. As a result, individuals who have a poor sense of smell or who suffer from a complete loss of the sense of smell tend to eat more than those with a normal sense of smell. Unsurprisingly, strongly flavored and seasoned foods – which often owe this property to spices – stimulate the satiety center far more effectively than bland foods, and we tend to eat less of the former as a result.

Distention of the stomach by food also induces the release of hormones that act as appetite suppressants and some foods, particularly the spices, have the same effects, even in the absence of stomach distention. A group of hormones called adipokines which are produced by fat tissue are also thought to play an important role in appetite regulation. Adipokines include the hormone leptin which is generally released in direct proportion to the amount of fat stored in the body, thereby helping the brain to gauge when there is a dearth or an excess of fat. Some obese individuals, however, appear to have genetic or other problems that impede the normal appetite-regulating effects of leptin.

Spices and Obesity
Spices have a number of properties that make them effective agents to help prevent and treat obesity. In their role as appetite suppressants, spices are known to work in three principal ways. The strong odors and flavors common to all spices rapidly stimulate the satiety center in the brain, thereby diminishing feelings of hunger. Certain spices, such as chilies, act by simulating the release of appetite suppressing hormones in the intestine. Garlic meanwhile reduces the appetite by increasing the brain’s sensitivity to leptin.

Another important anti-obesity property of spices is an ability to stimulate the nervous system to release hormones like adrenalin. These hormones speed up the metabolic rate which, in turn, helps “burn off” surplus fat. Capsicums (including chilies and red peppers) and garlic have been shown to increase the metabolic rate, in some cases by up to 10 percent. Clinical trials have demonstrated that these spices can be effective both in protecting against weight gain and assisting in weight loss. In the capsicum family, more than one phytochemical is known to be responsible for this effect: capsaicin (found in high amounts in chilies) and the less spicy capsiate (found in the milder paprika and red peppers) both increase metabolic rate. Some spices, including ginger , fenugreek and garlic reduce the absorption of fat from the intestines.

The diverse ways in which spices act provide the ideal combination of tools with which to help prevent weight gain and fight obesity. In conjunction with a sensible weight loss program, they are valuable adjuncts for us to use in the global fight against obesity.

 Anti-Obesity Properties of Key Spices

Anorectics (appetite suppressants)                      Chilies, garlic

Increase metabolic rate                                           Chilies, garlic

Reduce fat absorption                                              Fenugreek, garlic, ginger