Using research into the female biorythms, Body-clock Diet is a weight loss programme which is designed to fit in with the chemical fluctuations that occur in women’s bodies throughout the menstrual cycle.

Recommended for:

It is recommended for women who experience symptoms such as mood swings, food cravings, increase in appetite and fluid retention – all of which are associated with the premenstrual syndrome (PMS). These symptoms are usually experienced during the seven days leading up to the beginnings of menstruation. However, research has shown that many women experience physical and psychological changes up to the fourteen days before their period us due to start. Naturally, trying to sustain a diet when you are feeling depressed and moody or when you feel an irresistible urge for a chocolate bar can be extremely difficult.

Not recommended for:

It is not recommended for men; women who are going through or have already been through the menopause; women who are pregnant or breast feeding or who are trying to conceive.

Over a 24 hour period there are chemical fluctuations in the body that will affect mood, energy levels, appetite, the metabolism and blood-sugar levels. These fluctuations, known as ‘biorhythms’, can be profoundly affected by the hormones estrogen and progesterone which govern the menstrual cycle, resulting in the symptoms of PMS. The degree to which these are experienced is dependent upon the individual’s cycle; thus some women can experience an overwhelming urge for sugary foods several times a day, for up to two weeks before they are due to start their period. For other women the urge for something sweet may not be so strong and may be experienced only for the few days prior to menstruation

Irrespective of the individual differences, many women on a diet would agree that typical slimming foods – fruit, vegetables and low-fat foods – will neither satisfy these cravings nor their increased hunger. So the premenstrual phase is often a time when diets are broken and the dieter feels that she is back to square one.

Carbohydrates in the form of simple sugars (e.g., chocolate, sweets) or in their more complex form (bread, potatoes, paste, biscuits) are broken down rapidly during the digestive process (though this is more delayed in the case of complex carbohydrates). They give an immediate boost to the blood-glucose levels, satisfying both the hunger and the craving. However, this boost is not sustained and the cravings tend to be satisfied for a short period only.

The Body-clock Diet provides a questionnaire which enables the dieter to identify the nature of her own cycle and choose the diet plan which will be most appropriate for her. There are three diet plans based on a daily calorific intake from which the slimmer can choose:

  • Plan 1000 calorie diet – providing 1000 calories a day, it is recommended for women with 14 lb (6.3 kg) or less to lose.
  • Plan 1200 calorie diet – providing 1250 calories a day, it is recommended for women with 14 to 42 lb (6.3 to 19 kg) or less to lose.
  • Plan 1500 calorie diet – providing 1500 calories a day, it is recommended for women with 42 lb (19 kg) or more to lose.

Each diet plan is divided into three phases, each of which has a different calorie content and nutritional balance to match the changing body chemistry throughout the complete menstrual cycle. The first phase provides a dietary plan for the first part of the menstrual cycle from the first day of menstruation to around day fourteen. The calorie content is lowest during this phase and the emphasis placed on fruits and vegetables and starchy foods which have a high fibre content. In the second phase the menus feature predominantly low-fat foods with small amounts of sugary, starchy foods also included. In the third phase, the seven days immediately prior to a period when the mood swings, food curb cravings and increased appetite tend to be more prevalent, the daily calorific allowance is increased to enable the dieter to eat more sugary and starchy foods.

Each plan features a breakfast, a light meal and a main meal option with an added 100 calorie fruit allowance in the first phase. In the second phase an extra 100 calories allowance is made, to be chosen from fruit or from a list of suggested sugary and starchy treats for the Plan 1000 and the Plan 1250, while on the Plan 1500 the allowance for these treats is 250 calories. In the third phase the calorific allowance for extra snacks is a set at between 300 and 750 calories, depending on which plan the dieter has chosen as the most appropriate.

A Typical Day’s Menu

A typical day’s diet from Phase A on the Plan 1000 would be as follows:


1 boiled egg
1 rye crisp bread smeared with low-fat spread

Light Meal

1 whole meal pitta bread with 50 g (2 oz) hummus and 6 stoned black olives (in brine) served with a salad from the allowance for unlimited vegetables.

Main Meal

Mushroom omelette served with salad and oil-free dressing and a piece of fruit from the allowance or sausage hotpot and a piece of fruit from the allowance.

The flexibility of this programme enables the dieter to tailor the phases to her own needs. Thus, if you tend to experience food cravings only in the last seven days of your cycle you can stick to the first (and lowest) calorific phase of the diet at the first phase on the first day of your period or as near to that day as possible. As late menstruation begins the hormonal balance is restored to a state whereby the typical PMS cravings and hunger have diminished, making it the best time to maximise on a reduced food consumption. While in one phase you should not choose any of the menu options from the other phases as this will upset the nutritional balance that has been carefully devised for each phase.

Eating Out

There are no specific advice for eating out.

How fast is it?

The author cites that an average weight loss on the Plan 1250 covers over a 28-day period is 9.8 lb (4.4 kg); this figure is based on the experience of dieters who kept the Body-clock plan for at least eight weeks and includes fluid loss as well as fat loss.


The Body-clock diet also features an exercise programme, again divided into three phases to correspond to the stages of the menstrual cycle. This takes account of the fact that during the final phase of the cycle many women may experience a general lack of energy and disinclination to take part in physical activity. Each of the three exercise programme’s features exercises based on stretching, toning and aerobic movement to increase stamina, suppleness and strength. In addition, a chart of exercises from aerobics to yoga is provided giving the relative effects of each for stamina, suppleness and strength and the calorific expenditure per ten minutes.


The diet has a carefully devised readjustment programme which, once the dieter has reached her target weight, will enable her to increase her calorific intake gradually, without the classic pitfall of post-diet weight gain.

The positive philosophy behind the Body-clock Diet is that is it balanced with your body’s individual monthly cycle and your lifestyle. Full information about this diet is published in The Body-Clock Diet by Dr Alan Maryon Davies (Network Books, 1996)