The objective of the study was to determine the efficacy of Nutrico Diet® 7 and 14 days programs in weight management, including weight loss and changes in body measures. Yo-yo effect was also assessed (subjects were monitored for one week after completing the 7 or 14 days program), as well as the satisfaction with Nutrico Diet® program, including product taste, convenience of meal preparation, hunger and treatment success. Forthy six overweight subjects, of which 67% obese (BMI > 30), were enrolled in this clinical study.
During Nutrico Diet® 14 days program, including the maintenance period, subjects lost up to 10 kg, 4.7 kg on average (p<0.01).
During Nutrico Diet® 7 days program, including the maintenance period, subjects lost up to 6.1 kg, 3.8 kg on average (p<0.01).
Yo-yo effect did not occur in any group. In the maintenance period, during which one meal a day was replaced with an adequate Nutrico Diet® product, subject did not gain weight, on the contrary additional weight loss was observed.
Subjects with higher initial Body Mass Index (BMI > 30) lost more kilograms in comparison to subjects with lower initial Body Mass Index (BMI < 30), but in both study groups there was a significant weight loss.
During the study significant decrease in body measures was observed (waist, hips, thighs and upper arm circumference) in both groups.
Observed decrease corresponds to reduction of one to two clothing sizes.
According to the subject assessment, Nutrico Diet® program is efficient in weight loss. Program satisfaction was 98%.
Almost all of the subjects were satisfied with the product taste and the convenience of meal preparation.
Especially important fact is that most of the subjects did not feel hungry during the program, and the hunger was reduced even more as program moved along.
Based on the findings of this study it can be concluded that Nutrico Diet® program is highly efficient in weight management, leading to an average wight loss of almost 5 kilograms. At the same time, a decrease in body measures, which corresponds to reduction of one to two clothing sizes, occurs.
High satisfaction with program efficacy (98%) was noted, as well as high satisfaction with the taste (95%) and the convenience of meal preparation (98%). Majority of the patients did not feel hungry during the study which most definitely contributed to good subject compliance.
Protein diet research
It’s a known fact that obesity results from an imbalance in energy intake and consumption, and that hypo-caloric diet leads to weight loss. Besides a total reduction in calories, it’s also necessary to focus on meal composition, i.e. the proportion of proteins, fats and carbohydrates. The recommended daily intake of proteins is 0.8 g/kg1, while an increasing number of clinical trials have shown that meeting at least 25% of energy requirements using proteins leads to weight loss. There are three potential reasons for this.
Thermogensis – proteins consume more energy
The thermal effect of food is energy necessary for digestion and the absorption of consumed nutrients.
In practice, high-protein diets may have up to a 22% greater thermal effect than low-protein diets3. The University of Tuft in Boston discovered that foodstuffs containing on average 8374 kJ and 30% protein content resulted in additional consumption of 96 kJ a day when compared to foodstuffs with 15% protein content4. Even though at first this figure seems to be low, during the year it would lead to a weight loss of around 2 kg attributed only to thermogenesis. It is believed that the main reason for the greater “energy value” of proteins is the fact that human body cannot store protein reserves, but it immediately processes them5.
Typical thermal effect of proteins and carbohydrates2
Satiety – proteins suppress hunger
A number of studies have researched the effect of proteins on satiety. The research was conducted by allowing participants to consume meals with various percentages of carbohydrates, fats and proteins. Over a number of hours, the feeling of satiety was measured. The majority of research results showed that the intake of protein-rich foods (33-60% of the energy intake) was statistically and significantly positively correlated to a greater sense of satiety up to 24 hours after meals3. It isn’t altogether clear why proteins have this effect. One theory is that the satiety centre in the brain is sensitive to the level of amino acids (the building elements of proteins), and that when it reaches a certain point, the hunger feeling is “switched off”6. This makes sense when taking into account the importance of proteins for body growth and the maintenance of vital functions.
Reduced energy intake – eating less on account of proteins
Since we know that proteins increase the sense of satiety, the next logical step is to find out whether they lead to a reduction in energy intake. A number of studies provided positive results, while research conducted in 2000 showed that following the consumption of high-protein meals people consumed almost 200 kJ less in their next meal7.
What kind of results do proteins give?
Studies covering a period from few weeks to a year regularly showed better results in high-protein diets for weight loss when compared to those with low-protein intake. Interestingly enough, the protein diet regimes showed particularly good results in shorter time periods ranging from 2 to 4 weeks.
Study on 21 obese women. Low-calorie diet with 49% compared to 21% protein content8.
Study on 13 obese men. Low-calorie diet with 45% compared to 12% protein content9.
Study on 60 obese men. Foodstuffs with lower fat percentage, 25% compared to 12% protein content10.
- Smit E, Nieto FJ, Crespo CJ, Mitchell P: Estimates of animal and plant protein intakes in US adults, results from the Third National Health and Nutrition Examination Survey. J Am Diet Assoc. 99: 813–820, 1999.
- Westerterp KR, Wilson SAJ, Rolland V: Diet induced thermogenesis measured over 24 h in a respiration chamber: effect of diet composition. Int J Obes. 23: 287–292, 1999.
- Thomas L. Halton and Frank B. Hu: The Effects of High Protein Diets on Thermogenesis, Satiety and Weight Loss: A Critical Review. J Am Coll Nutr. (5): 373-85, 2004.
- Eisenstein J, Roberts SB, Dallal G, Saltzman E: High protein weight loss diets: are they safe and do they work? A review of the experimental and epidemiologic data. Nutr Rev. 60: 189–200, 2002.
- Mikkelsen PB, Toubro S, Astrug A: Effects of fat reduced diets on 24 h energy expenditure: comparisons between animal protein, vegetable protein and carbohydrate: Am J Clin Nutr. 72: 1135-1141, 2000.
- Mellinkoff SM, Frankland M, Boyle D, Greipel M: Relationship between serum amino acid concentration and fluctuations in appetite. J Appl Physiol. 8: 535–588, 1956.
- Araya H, Hills J, Alvina M, Vera G: Short-term satiety in preschool children: a comparison between high protein meal and a high complex carbohydrate meal. Int J Food Sci Nutr. 51: 119–124, 2000.
- Worthington BS, Taylor LE: Balanced low calorie vs high protein, low carbohydrate reducing diets. J Am Diet Assoc. 64: 47–51, 1974.
- Baba NH, Sawaya S, Torbay N, Habbal Z, Azar S, Hashim SA: High protein vs high carbohydrate hypoenergetic diet for the treatment of obese hyperinsulinemic subjects. Int J Obes. 23: 1202–1206, 1999.
- Skov AR, Toubro S, Ronn B, Holm L, Astrup A: Randomized trial on protein vs carbohydrate in ad libitum fat reduced diet for the treatment of obesity. Int J Obes. 23: 528–536, 1999.