The most important factors in weight-loss are:
- Eating a natural diet devoid of artificially processed foods.
- Being physically active each and every day.
- Eating modest amounts of sugary foods.
A natural diet
Processed foods are really the first port of call in any efforts to reduce weight. It was the increasing prevalence of junk food in our diet from the 1960s onwards that led to the increasing rates of obesity over the same period. The reason they cause weight gain is based on a number of factors including:
- The presence of artificial additives. Processed foods are virtually all full of additives, many of which can lead to weight gain. Artificial sweeteners, excess sugars and salt, flavour enhancers, preservatives, artificial colours and emulsifiers all disrupt our metabolism. Some are worse than others but their net effect is normally to encourage weight gain. Some, like excess sugar are an obvious source of excess calories, however many others increase appetite leading to more calorie intake, and many of the other additives disrupt various aspects of metabolism. This often leads to long term weight gain by changing hormone levels or other through less obvious mechanisms.
- The association of junk food with bad eating habits. Wherever you eat junk food you are likely to increase the chances of gaining weight. Eating in a junk food restaurant setting involves easy access to many unhealthy, cheap and tempting foods. It encourages faster eating with less time for proper digestion and also eating on the move if the meal is taken outside the restaurant. Eating junk food or takeaway meals at home encourages eating in front of the television or computer screen, which has been show to slow metabolism down more than sleeping. The food is not properly digested when sitting in a slouched position in front of a screen. Also your concentration on the screen adversely affects the way your body responds to the natural cues of eating, such as the sight and smell of foods, which help you produce the enzymes and gastric juices you need to properly digest the foods you are eating.
An active life
So how does exercise lead to weight loss?
- For some people, especially those who are morbidly obese, being completely sedentary is a big part of the problem. Even small amounts of daily exercise burn calories and restore hormone levels so that more can be burnt at rest. These people will benefit from a short walk and standing rather than sitting for a few hours each day.
- For those who are young enough or slim enough regular bouts of intense exercise can really boost the metabolism leading to more calories being burnt at rest.
- The same effect may be achieved by those who commit to vast quantities of exercise (six+ hours per week) such as training for marathons, triathlons and cycling time trials.
There are some people who do plenty of exercise but do not lose weight. In the vast majority of cases this is either due to the rest of their life being sedentary or their diet containing too much processed food.
Dietary sugar, fat and fibre
For most people, dropping the amount of sugar in the diet is more effective than reducing fat. The medical profession including dieticians currently favour less fat, the nutritional profession currently favour less sugar. There is evidence that both can work, but the most persuasive trials show that restricting carbohydrates is more often effective. How does it work?
- Restricting carbohydrates, which all break down into sugars in the gut, reduces levels in the blood of the hormone insulin. Insulin is our “rest and digest” hormone that helps store foodstuffs such as fat in our cells. Sugar can be converted into fat for storage also, so for example, a doughnut has white bread and sugar to increase insulin levels, and is deep fried in fats, giving a perfect recipe for weight gain.
- Restricting fat can lead to weight-loss often due to calorie reduction. Fat makes food more palatable, increasing the potential for overeating. However, insulin levels may remain high, and so a low fat diet will require less food to be eaten than a low carbohydrate diet.
- Fibre from fruits and vegetables can have a big impact on how effective either low-fat or low carb diets are at weight loss. They can change the bacterial populations in your gut allowing you to absorb more or fewer calories from your food and change transit times of food going through your system which also affects how any calories you can absorb.