Extreme weight loss or quick weight loss is defined against normal weight loss goals. In the average diet plan, losing one to two pounds (.45-.91 kg) per week is usually considered optimal. When people lose more than two pounds (.91 kg) per week, especially for several weeks at a time, this is considered fast, and significantly greater amounts can be considered extreme weight loss. While some people advocate this for the average person, most people suggest such heavy loss is only suited for the morbidly obese or only expected in those who have undergone bariatric surgery.
There are many people who want to shed weight quickly, perhaps in a couple of week’s time for some form of special event, such as a wedding, prom, or high school reunion. Dieters are usually better-served by planning to lose a little bit each week instead of trying crash diets that may temporarily drop a higher amount of poundage. Extreme weight loss of this sort lends itself to the yo-yo dieting problems so many encounter, and is often followed by, with rapid discontinuation of a diet, weight gain that equals or exceeds the loss. Changes in diet and exercise patterns that are easier to maintain and continue and that do not contribute to a sense of total food deprivation or nutritional loss are much more healthful.
Most forms of extreme weight loss that are non-surgical are composed of two factors. People eat a very low calorie count or in other ways have highly restricted diets like avoiding all carbs or only drinking liquids. This is usually combined with a high level of exercise, typically an hour or more a day. Large amounts of fluids are consumed to shed excess water weight and to help deal with hunger. This type of plan can notably backfire, since some people’s bodies slow down in response to the low intake of food and extra exercise. This can cause weight gain instead of loss.
The amount to which extreme weight loss is problematic increases with the amount of time spent using such a diet. Some people jumpstart a more moderate diet with a week or two of extreme dieting and others like the quick weight loss results of fast weight loss and keep pursuing aggressive dieting and exercise. The latter group is more at risk for nutritional deficits because very low calorie intake may not adequately support nutritional needs. Sometimes diet plans compensate for this through adding nutritional supplements, but these may not be enough.
Another definition of extreme weight loss is losing large amounts of weight over an undefined time period. This is common in people who have weight loss surgery and also those people who were formerly very obese and found other ways to lose the weight. It’s conceivable for people to lose hundreds of pounds; this is thought useful if it results in healthy weight maintenance. Surgical weight loss methods do create ongoing health and nutritional risks, and these require consideration.