Weight gain or a weight-loss plateau, even when you are trying to lose excess weight by limiting calories, can have many causes beyond diet. If that sounds familiar, there is little point starving yourself: it will not help. The key is to work out what is driving the problem and address it.

Young woman half-awake in a bed with crumpled sheets, in the soft light of dawn

There are times when, however careful you are with food, however much exercise you do and however diligently you apply slimming cream, nothing shifts: weight gained recently or gradually over the years stays put, without even a flicker on the scales. And while you wonder what could be stopping you losing weight, you fixate on the occasional treat you allow yourself, wondering whether that too has to go. Looking after your figure is one thing, but you can only cut back so far: who knows, your love handles may have nothing to do with what you eat, or may simply come down to poor food choices...

Young woman preparing a plate of protein and pulses in a very bright kitchen

Here are some factors that may be involved in weight gain or in stalling weight loss, because weight is not only about calories consumed: it also depends on physical and psychological factors.

First, are you on the pill?

The available data do not allow us to conclude that the pill has a direct effect on weight, even though some women report changes in appetite or water retention. This retention—whether linked to the pill or to a diet too high in salt—can make you feel bloated and give the impression of weight gain when it is really excess water stored in the body, in blood vessels and tissues. If you notice abnormal swelling in parts of your body, especially your ankles and feet, or a feeling of heaviness, speak to your GP, who can identify the cause clearly and advise on treatment. And if weight gain remains unexplained, your GP is also the person to turn to.

Pack of contraceptive pills and a glass of water on a bathroom counter in morning light

Stress

Stress is already blamed for anxiety, depression and a whole range of physical and psychological complaints. It can also play a role in many cases of weight gain, even though the precise mechanisms, such as NPY, are still being studied. And we all know, unfortunately, the reflex of reaching for a tub of Nutella to make up for a stressful day; but stress also acts through other, subtler pathways—appetite, sleep and food choices. There is a lot to gain from getting rid of stress, which is far from easy, certainly, but necessary.

To start with, think about exercise, relaxation, yoga... there are all kinds of activities to suit different temperaments that can help release stress and everyday problems...

The wrong kinds of fat

You probably already know that not all fats are equal: some are good for health (in reasonable amounts) and gentler on our waistlines, while others are responsible for bad cholesterol and contribute greatly to the risk of cardiovascular disease.

Among the fats to limit are industrial trans fats, created by processing vegetable oils that are modified by hydrogenation, usually to turn them from liquid to solid: what began as vegetable oils no longer retains the qualities of the original vegetable oil. And they are not the only ones: saturated fats, even when not industrially hydrogenated, also contribute to raising LDL cholesterol and should be limited.

So prefer to dress and cook with vegetable oils that you vary (walnut, rapeseed, olive, sunflower, hazelnut...), and be wary of pastries, cakes and savoury snacks: often very fatty, and sometimes made with partially hydrogenated fats—check for partially hydrogenated oils in the ingredients list.

In the same way, more generally, it is about making the right choice between foods that seem identical but do not act the same way when digested. This is particularly true of wholegrains and refined grains: refined grains often have a high glycaemic index and can trigger an insulin spike when digested, whereas wholegrains usually do so less—the glycaemic index varies according to the type of grain and how processed it is. They are also digested quickly, which may encourage cravings more than wholegrains, which are higher in fibre and therefore beneficial for digestion.

Persistent, mounting tiredness

A lack of sleep can play a role in hunger and, in some people, in weight gain, although the effects vary greatly from one person to another. So, again, it is an essential point for both health and weight: sleep enough and, if your night was short and you have the opportunity, think about a short nap after lunch.

Gut flora out of balance

Here too, research is exploring the role of the microbiome in weight regulation and calorie absorption, but the data do not yet allow a definitive conclusion. Many bacteria are present in the gut, but contrary to what you might think, some of these bacteria are beneficial. In the hypotheses being studied, when 'bad' bacteria accumulate at the expense of 'good' ones (simplified, admittedly, but it sums up the importance of a healthy gut flora), weight gain of varying degree could occur even when the number of calories consumed remains the same.

When faced with an imbalance in gut flora, some approaches aim to encourage a balanced and diverse microbiome, rather than directly eliminating undesirable bacteria. Certain foods can help, including artichokes, onions, chicory and fibre-rich foods...

In fact, there is a lot of talk today about probiotics: probiotics are live micro-organisms; their value for a balanced and diverse microbiome is still being studied, with no definitive conclusion to date.

As for bifidobacteria, also often mentioned for a healthy gut flora, these are found in particular in some dairy products under the name bifidus.

We should not forget medicines either: if your weight changes without explanation, speak to your GP, who can also review your current treatments.

Finally, a thyroid disorder is one of the causes your GP may investigate for unexplained weight gain. If you have any doubts, do not hesitate to make an appointment.

In practice, remember this: before you embark on weeks of restriction, go through the possible causes—sleep, stress, salt, processed fats, medicines. Unusual swelling, persistent tiredness or unexplained weight gain deserve advice from a healthcare professional, rather than starving yourself in silence.