XII.A. Lifestyle modification
The most effective therapy is a weight loss. A weight loss of more than 7% significantly improves the MetS parameters. A 3% decrease of the systolic BP causes an 8% decrease in the risk of stroke.
There are various possibilities to attain a weight:
a. Physical activity
The most important is continuous exercise for at least 30-40 min at least 3-4 times weekly. Continuity is more important than the intensity of the physical activity. Swimming is particularly recommended for obese patients, because this movement burdens the joints least.
Comparative studies of the beneficial effects of physical activity and a healthy diet on T2DM have found that a healthy diet causes a 30-35% amelioration, and physical activity (at least 150 min/week) causes a 40-45% amelioration in T2DM, and a combination of a healthy diet + physical activity leads to a 50-75% amelioration.
The recommended forms of regular physical activity:
4-5 km walking daily or
8-10 km cycling daily or
2-3 km running daily or
100 m swimming daily.
Swimming is the most recommended activity, because
it has less impact on the joints of obese people,
various muscle groups are moved,
it burns energy not only through movement, but also through regulation of the body temperature.
b. Nutrition
It is important to pay attention to appropriate energy and nutrient intakes during eating.
The health effects of some food ingredients are mentioned below:
Foods containing antioxidants
Special diets can decrease the level of inflammatory markers typical of the MetS (CRP and IL-6). Such food ingredients include plant sterols, soy protein, viscous fibers, vegetables, almonds, nuts, red wine, fresh fruits and olive oil as MUFAs.
They decrease the TG and total cholesterol levels and increase the HDL level.
Fish oil products
These decrease the TG and fat levels in the liver, and the BP.
A diet high in carbohydrates
High TG and low HDL levels and insulin resistance develop.
The PAI-1 level increases and fibrinolysis is inhibited.
Starchy foods have a high glycemic index (GI) and are digested easily and rapidly absorbed. The blood Glu level therefore increases rapidly and significantly. Foods with a low GI are usually fiber-rich (except for rice and some forms of pasta).
Foods high in fructose
The MetS may develop following the consumption of foods containing a large amount of fructose.
Fructose causes insulin resistance, a weight gain, hyperlipidemia and hypertension. The regular (1 glass daily) consumption of soft drinks (even with sugar or with sweetener) increases the risk of the MetS.
The nature of the carbohydrate consumed is not important if its total amount is low, and the amount of energy too is low.
Diet with decreased carbohydrate content (CHO <30 g)
This decreases the body weight, and the blood FFA and TG levels. The BP and inflammation decrease, and the tissue insulin sensitivity increases.
A high cholesterol intake
A cholesterol intake of more than 300 mg/day is a means cholesterol-rich diet.
In egg yolk, goose liver, sausage, marrow and offal, the cholesterol level is high. (1 egg yolk contains 220 mg cholesterol.)
A high daily fat intake (above 30%)
The insulin sensitivity decreases, and the insulin release increases.
Such a fat intake decreases the endothelial NO production, and therefore induces vasoconstriction.
Saturated fatty acids
The insulin resistance and the cholesterol level increase.
Polyunsaturated fatty acids (PUFA)
The insulin sensitivity increases, while the VLDL and TG levels and the BP decrease.
The following contain mainly ω-3, ω-6 or ω-9 fatty acids:
olive oil, nut oil, rapeseed, soybean and linseed oil.
The following contain other PUFA: mackerel, trout, herring, salmon and tuna.
High monounsaturated fatty acids (MUFA)
These enhance insulin sensitivity, and slightly decrease the BP.
20-40% MUFA nuts (nut), soybean and sunflower seeds
40-50% MUFA nuts (peanuts)
50-60% MUFA olive oil, olive, rape oil, margarines, oilseeds and nuts (chestnuts)
60-80% MUFA nuts (peanuts, pistachios and almonds)
The effects of saturated and unsaturated fatty acids differ only when they are consumed in higher doses daily.
Trans fatty acids (TFA)
The data are inconsistent. For example, conjugated linoleic acid (CLA), which can be found in foods containing hydrogenated vegetable oil, decreases the insulin sensitivity and may cause diabetes mellitus in healthy people. However, CLA treatment has an anti-diabetogenic effect in obese individuals.
A low daily fat consumption (below 30%)
This causes a weight loss.
A diet with decreased carbohydrate and high fat contents
This causes a weight loss.
A diet with high protein content (>8 g/kg/day)
This leads to a weight loss and the decrease of fat mass, but the consumption of much protein causes a decrease of insulin sensitivity.
A fiber-rich diet
This decreases sugar absorption, enhances insulin sensitivity, and decreases the abdominal fat mass and the CRP level.
Fermentable or soluble fibers (e.g. oat):
These decrease the blood Glu and LDL levels.
Vitamins
A low vitamin D level decreases insulin production. A decreased Ca2+ level decreases insulin production too and the activity of GLUT-4.
A high vitamin D level increases the insulin sensitivity.
Trace elements
Magnesium is a cofactor in various processes: it increases energy use, the regulation of Glu, insulin and BP, etc.
A low Mg2+ level enhances the risk of the MetS. Mg2+ treatment (2.5 g/day, during 3 months) decreases the TG and cholesterol levels, and increases the HDL level.
A diet with high salt content (8.6 g/day)
This enhances the BP.
Alcohol
In small amounts (1-2 glasses of wine per day), alcohol enhances the HDL level, decreases coagulation and is an antioxidant (it decreases lipid peroxidation).
In large amounts, it increases the TG level and fat deposition and enhances the appetite. Alcohol consumption can therefore cause a large energy intake. It inhibits fat oxidation and increases the BP.
When the various diets are compiled, the food GI index (the speed of breakdown of the food to sugar) and the energy content of the food in terms of its fat, carbohydrate and protein contents should be monitored.
Calorie needs
The necessary daily intake for 22-year-olds is about 2000-2800 cal. The calorie needs depends on the gender, the height, the outside temperature, the physical activity and the age. The calorie needs of men are larger. Physical work and sport increase the calorie intake. The calorie needs are lower in warmer climates and as the age progresses.
The main aspects of a diet
Calorie restriction
A 500-1000 cal restriction daily at least is needed to attain a weight loss. 1000 cal is most widely accepted for the daily calorie intake, when the calorie deficit is 1800 cal, which means about 15-20 kg of fat. The weekly weight loss in this case is 1-1.5 kg.
The composition of the food
The recommended ratio: 40 g of carbohydrate, 60 g of fat, 75 g of protein.
Meal frequency:
The consumption of 1-2 meals containing meal daily increases the serum cholesterol and Glu levels. It decreases the Glu tolerance, which is followed by enhanced lipolysis, and leads to obesity. For a weight loss, frequent (3-5 times) and low calorie-containing meals are recommended:
breakfast - 200 cal
brunch – 100 cal
lunch – 400 cal
snack – 100 cal
supper – 200 cal
The following diet composition is recommended for MetS patients:
Components Percentage total energy (TE)
Carbohydrates1 45-60%
– sugars < 10%
Protein 15-25%
Total fat2 25-30%
saturated fatty acids < 8%
high monounsaturated fatty acids 10-20%
polyunsaturated fatty acids 5%
Cholesterol < 200 mg
Fiber 30-40 g/day
(half of this preferably in soluble form)
1 The carbohydrate sources should be from low-GI foods: vegetables, pulses, fruits and whole grain cereals.
2 TFAs should be avoided if possible.