I found an interesting article on the internet (that appears to be based on scientific evidence) about weight loss plateaus, why they happen and what to do about them:
Lessons from this article specifically for us 5:2 dieters would be to watch that we are not increasing carbohydrate intake on feast days and at the same time to ensure that our definition of normal eating on feast days fits with our decreasing weight! We may also need to recalculate our fast day allowance (i.e. 25% of the new 'normal').
Weight loss plateaus: why they happen
Plateaus are a common part of the weight-loss process. A plateau happens when the scale is at a standstill for several weeks - if weight stays the same for one or two weeks or the rate of weight slows but doesn't stop, it's not a true plateau. The progression from initial weight loss to hitting a plateau follows a typical pattern.
The predictable cycle of weight loss
During the first few weeks of losing weight, a rapid drop in weight is normal. When calories from food are reduced, the body gets needed energy by releasing its stores of glycogen, a type of carbohydrate found in the muscles and liver. Glycogen holds onto water, so when glycogen is burned for energy, it also releases the water - about 4 grams of water for every gram of glycogen - resulting in substantial weight loss that's mostly water.
Once the body uses up its glycogen stores, it starts to burn fat for energy. Unlike glycogen, fat does not store much water and each gram of fat releases more than twice the amount of energy (i.e. calories) than a gram of glycogen. The result is that weight loss slows down substantially. At this point, the recommended rate of weight loss is no more than an average of one kilogram per week. Losing weight faster than this is generally a sign that amounts of lean muscle mass, which like glycogen is largely water, are being broken down for energy.
As the body's glycogen stores are replenished by increased carbohydrate intake, there is a corresponding retention of water. During this time, weight stabilises or may temporarily increase.
Why weight loss plateaus happen
By six months, a weight loss plateau is likely to occur. While plateaus are an almost inevitable response to losing weight, the physiological reasons for why they occur is not well understood.
One area of current research involves a possible link to reduced levels of leptin, a hormone produced by fat cells that is involved in the regulation of appetite. Research has shown that weight loss causes a marked decrease in serum leptin levels, which may, in turn, increase appetite. Based on evidence from an animal study, scientists have suggested that a reduction in leptin may contribute to a weight-loss plateau. However, more research on leptin's role in human weight regulation is needed before conclusions can be drawn.
Metabolic processes during weight loss may also impact plateaus. Losing weight can lower metabolism since a smaller body carries less lean muscle mass and burns fewer calories to move it around. Additionally, lower calorie intake means it takes fewer calories to digest and absorb food. Taken together, a state of energy equilibrium could result, with weight remaining steady for a period of time.
Exercise is a plateau breaker
Increasing physical activity can help break through a plateau. Exercise burns calories and may reduce the loss of lean muscle mass during weight loss. Aerobic exercise, like brisk walking and biking, burns calories, while resistance exercise builds lean muscle which increases energy expenditure and helps boost metabolism.
Fluid retention, which may result from high sodium consumption or premenstrual bloating, can contribute to a plateau. Additionally, research suggests that obesity increases fluid volume and the imbalance in fluid regulation that accompanies obesity does not normalise after weight loss. Still, fluid balance varies considerably among individuals. It's been reported that drinking more water and increasing exercise reduce fluid retention and help people work through a plateau, but scientific evidence supporting this recommendation is lacking.
A change of pace
Over time, the body adapts to doing the same aerobic or strength training routine. As training progresses, the organs that transport oxygen, including the lungs, heart, muscles and blood vessels, work more efficiently and with less effort. For example, the lungs take in and release more air in a single breath, so there is less "huffing and puffing" during exertion; the heart pumps more blood in a single stroke, which lowers the heart rate; the blood gets diverted to muscles more efficiently. Consequently, less energy is expended during activity, which can slow weight loss or lead to a plateau.
Increasing the time spent doing an activity or the intensity of the activity can increase the calories burned during exercise. Changing a workout with a new activity or alternating between different activities can help prevent the muscles from becoming too accustomed to doing one type of exercise.
Keep expectations reasonable
There is no question that a weight loss of 5% to 10% of initial body weight improves health, reducing the risk of diseases such as heart disease, type 2 diabetes and high blood pressure. Despite this, research has found that overweight individuals often desire weight losses two to three times more than this amount. In one study that included obese women, a 17% weight loss was viewed as "disappointing" by the participants and it took a 25% weight loss for the rating to be "acceptable."
The gap between realistic and desired weight goals can lead to a "discounting" of the results that are achieved. Some studies suggest that having unrealistic weight-loss goals can work against consistently making the behaviour changes needed for lasting weight loss. Moderating expectations, particularly as they relate to the speed with which weight-loss is achieved, may help keep weight-loss efforts on track.
Refocus weight goals
Experts agree that a 10% weight loss of initial weight over a period of six months is both realistic and attainable. After six months, however, it is common for weight loss to plateau.
There are several factors that contribute to weight-loss plateaus. For example, familiarity with a weight-loss plan often leads to a relaxed adherence in eating or exercise regimens. In addition, the number of calories needed for metabolism is reduced as weight is lost. To counteract this and resume the recommended rate of weight loss, a further decrease in food calories and/or increase in calories burned in physical activity are needed.
If weight loss plateaus after six months of active dieting, experts often recommend a reassessment of weight-loss goals. For many, a refocusing of efforts to maintain the weight that has been lost as opposed to continuing active weight loss may be desirable. After a few months of weight maintenance, a return to active weight loss is reasonable.
Lessons from this article specifically for us 5:2 dieters would be to watch that we are not increasing carbohydrate intake on feast days and at the same time to ensure that our definition of normal eating on feast days fits with our decreasing weight! We may also need to recalculate our fast day allowance (i.e. 25% of the new 'normal').
