Obesity is being defined as more than 20 % above the ideal weight. It is an issue in most western countries and in New Zealand has been rising since the 1970’s. Being overweight, which is defined as anything above your ideal body weight up to 20%, has also increased in most countries including New Zealand.

The cause of obesity is multifactorial. Idiopathic obesity is assumed to be due to an imbalance between food intake and energy expenditure, basically eating more than needed for a person’s body size without the physical activity and proper exercise. This is fairly common, with the availability of processed, high calorie foods.

Some medical conditions can be contributing factors in obesity and weight gain. Endocrine disorders may cause obesity. These would include: excess insulin (Type II Diabetes) excess cortisol (Cushing’s syndrome or corticosteroid drug use), hypothyroidism and hypothalamic disorders. Excess weight gain may also be caused by estrogen dominance, where for both men and women elevated levels of estrogen cause android or central obesity. This is an accumulation of fat around the abdomen (which may also be called beer belly in males) as opposed the hips (gynoid obesity).

Psychological factors may be present, some think as a cause of weight gain but more as a result. Eating patterns associated with depression and deviant eating patterns, such a binge eating disorder and night-eating syndrome can cause weight gain. But more likely is a general sense of depression and alienation, as people and females in particular can view problem with weight as a source of prejudice and discrimination.

A sedentary lifestyle as an independent risk factor of obesity should be noted, as television watching has been demonstrated to be linked to the onset of obesity. This can be explained by the lack of physical activity and lowering of the basal metabolic rate, the rate of energy our body create in order to perform the physiological functions. Also important to note, exercise tends to be lower in those who watch a lot of TV. The intake of food may not be lower in these people who exercise less and may even be more, contributing even more to weight gain.

Other risk factors for obesity include: parental obesity; pregnancy; high fat diet; some medications such as antidepressants and oral steroid hormones; and low socioeconomic status.


Many people realize that they may have a problem with weight without any physical symptoms. A change in clothing sizes is one indication that people of both sexes may notice, even if other factors are not present.

Obesity and weight gain may lead to joint problems such as seen with osteoarthritis; skin conditions due to increased sweating, and can lead to problems regulating blood sugar, diabetes and cardiovascular disease.

Lifestyle and Dietary Modifications

The effect of exercise alone (without dietary restriction) on weight loss is small, partly because muscle mass often increases even while fat tissue is reduced, and perhaps because some exercising people will experience increased appetites. The long-term effect of regular exercise on weight loss is much better, and exercise appears to help people maintain weight loss. People who have successfully maintained weight loss for over two years report continuing high levels of physical activity. Combining exercise with healthier eating habits results in the best short- and long-term effects on weight loss, and should reduce the risk of many serious diseases. This also may help with people who experience “weight cycling” (repetitive weight loss and gain), who have a tendency toward binge eating. The most successful weight-loss programs (in which weight stays off, mood stays even, and no binge eating occurs) appear to use a combination of moderate caloric restriction, moderate exercise, and behaviour modification, including examination and adjustment of eating habits.

When overweight people attend group sessions aimed at changing eating and exercise patterns, keep daily records of food intake and exercise, and eat a specific low-calorie diet the outcome is much more successful. Group sessions where participants are given information and help on how to make lifestyle changes appear to improve the chances of losing weight and keeping it off. Such changes may include shopping from a list, storing foods out of sight, keeping portion sizes under control, and avoiding fast-food restaurants. Behavior-change techniques are considered useful for helping people break old habits and form more healthful habits. These techniques may be learned from counselling professionals, support groups, educational programs, or books.

Problem-solving techniques are used in some types of counselling to help people maintain changes in their behaviour.

Calories in the diet come from fat, carbohydrate, protein, or alcohol. Dietary changes to reduce weight may be geared at any limiting calories from one of these elements and/or by emphasizing foods that are believed to result in reduced calorie intake. Some currently popular diets restrict fat while emphasizing fibre and a balanced intake of healthful foods. Others restrict carbohydrates, either to extremely low amounts as in the Atkins diet, or to a lesser degree, emphasizing foods low in the glycemic index or high in protein

Low-fat, low-calorie, high-fibre, balanced diets are recommended by many doctors for weight loss. According to controlled studies, when people are allowed to eat as much food as they desire on a low-fat diet, they tend to lose more weight than people eating a regular diet. However, low-fat diets have not been shown to be more effective than other weight-loss diets that restrict calories. Nonetheless, a low-fat, high-fibre, balanced diet has additional potential benefits, such as reducing the risk of chronic diseases including cardiovascular disease and cancer

Low-carbohydrate, high-fat diets such as the Atkins diet are very popular among people trying to lose weight. An analysis of preliminary studies of this type of diet concluded that its effectiveness is primarily due to reduced calorie intake. The effect of low-carbohydrate diets on cardiovascular risk is also an unresolved issue. Some studies have shown a worsening of certain cardiovascular risk factors in people using a low-carbohydrate, high-fat diet for up to one year. Adverse changes included increases in blood levels of homocysteine, lipoprotein(a), and fibrinogen, and a decrease in blood flow to the heart. Individuals wishing to consume a very-low-carbohydrate diet for weight loss or for other reasons should be monitored by a doctor.

Diets that emphasize choosing foods with a low glycemic index have been show to help control appetite in some studies. Glycemic index and glycemic load describe the tendency of foods to raise blood sugar. Eating meals containing foods that are low in glycemic index or glycemic load may influence appetite and other body mechanisms that affect excessive weight gain. Most low qlycemic foods are high in fibre and adequate amounts of dietary fibre are believed to be important for people wishing to lose weight. Fibre adds bulk to the diet and tends to produce a sense of fullness, helping people consume fewer calories. A recent review of weight-loss trials that did not restrict calories concluded that higher fibre diets improved weight-loss results, especially in people who were overweight.

Although the relationship between food sensitivities and body weight remains uncertain, many believe that chronic food allergy may lead to overeating and obesity. It is thought that this is a result of a craving of the offending foods, leading to overacting. By identifying and stabilising food sensitivities many people experience an increased energy level due to a healthier diet.

People who go on and off diets frequently complain that it takes fewer calories to produce weight gain with each weight fluctuation. Evidence now clearly demonstrates that the body gets “stingier” in its use of calories after each diet. This means it becomes easier to gain weight and harder to lose it the next time. Dietary changes need to be long term.

Nutritional Factors Shown to be Beneficial

Multiple vitamin minerals

Diets that are low in total calories may not contain adequate amounts of various vitamins and minerals. For that reason, taking a multiple vitamin-mineral supplement is advocated by proponents of many types of weight-loss programs, and is essential when calorie intake will be less than 1,100 calories per day.
Dose: as recommended on bottle


In a study of obese people consuming a low-calorie diet for 24 weeks, those receiving a calcium supplement lost significantly more weight than those given a placebo. It is possible that calcium supplementation enhances weight loss only when the diet is low in calcium.
Dose: 800 mg a day


The mineral chromium plays an essential role in the metabolism of carbohydrates and fats and in the action of insulin.
Dose: 200 mcg a day


5-hydroxytryptophan (5-HTP), the precursor to the chemical messenger (neurotransmitter) serotonin, has been shown in three short-term controlled trials to reduce appetite and to promote weight loss. This may be due to increased well being and energy level.
Dose: 50 mg three times per day with meals


Fibre supplements are one way to add fibre to a weight-loss diet. Fibre can add to the bodies’ detoxification process, by encouraging normal bowel movements and increasing the solubility of bile.
Dose: as recommended on bottle


Pyruvate, a compound that occurs naturally in the body, might aid weight-loss efforts. Some studies suggest that pyruvate supplementation leads to weight loss by increasing the resting metabolic rate.
Dose: 3-6 grams a day


Conjugated linoleic acid (CLA) is thought to increase metabolic rate, decrease abdominal fat and enhance muscle growth. It may also lower resistance to insulin, a factor in diabetes type II.
Dose: 2-4 g a day with meals


Hydroxycitric acid (HCA), extracted from the rind of the Garcinia cambogia fruit grown in Southeast Asia, has a chemical composition similar to that of citric acid (the primary acid in oranges and other citrus fruits). Preliminary studies in animals suggest that HCA may be a useful weight-loss aid.
Dose: 1000 mg before meals

Whey protein

Whey protein may aid weight loss due to its effect on appetite. In studies whey protein consumption resulted in more hunger satisfaction and reduced the amount of food eaten compared with other protein powders. Protein powders work will taken in the morning for those with sugar cravings early in the day.
Dose: as directed on bottle

Green Tea Extracts

Green tea extract rich in polyphenols (epigallocatechin gallate, or EGCG) may support a weight-loss program by increasing energy or by inhibiting the digestion of fat in the intestine. Although green tea does contain caffeine and caffeine is known to stimulate metabolism, it appears that other substances besides caffeine were responsible for at least part of the weight loss. Attempting to drink enough green tea to achieve health benefits can lead over consumption and may cause irritability, insomnia, nervousness, and tachycardia.
Dose: 500-1500 mg of extracts standardized 80% total polyphenols.

Gymnema (Gymnema sylvestre)

Gymnema improves the ability of insulin to regulate blood sugar, and is helpful when dealing with food cravings.
Dose: 400-600 mg a day

Diagnosis and Pharmaceutical Interventions

The diagnosis of obesity and weight gain is quite simple and is sometimes only gauged with observation. For exact measurement, the body mass index (BMI) is calculated. This is determined by calculating weight in kgs by height in meteres squared. BMI’s indicate the range of body sizes, as underweight is defined as being 18.5, normal weight is 18.5-24.9, overweight is defined as 25.0-29.9 and obese is defined as 30.0 and above.

Pharmaceutical medications for obesity and weight gain may fall in and out of favor by both the public and medical professional depending on the efficiency and potential side effects. Some medications that may be used are diethylpropion (tenuate), phentermine (umine) and sibutramine (reductil). These medications should be discontinued after 12 weeks if failure to achieve a weight reduction of 5% has not happened. They should not be used in cases of advanced arteriosclerosis, hyperthyroidism, known hypersensitivity, or idiosyncrasy to the sympathomimetic amines, glaucoma, agitated states, and patients with a history of drug abuse. Phentermine in particular should not be used in alcoholic patients weather it is active or in remission. In rare cases the use of these medications has been associated with an increased risk of developing primary pulmonary hypertension (PPH), a rare but often fatal disorder. Other side effects include elevation of blood pressure and overall central nervous system stimulation such as jitteriness, blurred vision, dry mouth, changes with libido, loss of appetite, insomnia and depression.

Because of the range of side effects from these medications; one option that has gained popularity in the treatment of obesity is the surgical intervention of gastric bypass, or stomach stapling. It is usually done when the BMI is over 40 and other treatments have not worked. This decreases the size of the normal stomach, creating a stomach that sometimes is no more than 25 ml in volume. As a complication from this procedure, some vitamins may become deficient, especially ones that are absorbed in the stomach like vitamin B12.

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