Table 1 Description of included reformulation studies

Gatenby SJ, 1995

USA

To assess the nutritional implications of the purchase and consumption of reduced-fat foods at home in normal-weight, free-living consumers.

Ages (mean age 40 yrs)

Total n completed = 29

Randomized trial for 6 weeks.

1) Experimental: Use reduced-fat foods ad-libitum in place of traditionally high-fat foods.

2) Control: Habitual diet.

1) 4 d weighed food diaries

2) Body weight

1) The low fat group reduced their % of energy from fat vs. control at 6 weeks (mean ± SEM: 38.3 ± 1.8 % to 30.4 ± 1.7 % vs. 37.9 ± 1.9 % to 39 ± 4 %, P = 0.001).

2) The low fat group increased the % of energy from protein (17 ± 11 % E vs. 15 ± 0.5 % E, P = 0.06) and carbohydrate (49 ± 2 % E vs. 46 ± 2 % E, P = 0.019) vs. control.

3) NS in mean ± SEM total energy intake between experimental and control groups (1939 ± 598 kJ vs. 1887 ± 417 kJ, P = 0.63).

4) NS in mean ± SEM sugar intake between experimental and control groups (109 ± 11 g vs. 99 ± 15 g, P > 0.05).

5) The low fat group lost 1.1 kg (P < 0.001) while the control group had a non-significant gain of 0.4 kg (mean ± SEM baseline to final weight in experimental: 74.6 ± 4.5 kg to 73.5 ± 4.3 kg; control: 65.4 ± 2.9 kg to 65.7 ± 2.8 kg).

Gatenby SJ, 1997

USA

To expand and extend the previous study (above) while also contrasting the effects of fat and sugar replacement.

Ages: 18-50 yrs

Total n completed = 65 females

Randomized trial for 10 weeks.

1) Reduced fat: Use reduced-fat foods ad-libitum in place of habitually consumed foods with traditional composition.

2) Reduced sugar: Use reduced-sugar foods ad-libitum in place of habitually consumed foods with traditional composition.

3) Control: Maintain usual diet.

4 d weighed food diaries

1) NS overall main or interactive effects of group for energy intake, sugar intake; however all groups reduced their sugar intake (data not reported in paper).

2) Compared with the reduced sugar and control groups, the reduced fat group reduced their fat intake significantly during the intervention period from ~37 % E from fat at baseline to 33 % E from fat at week 10 (P  = 0.017).

Gunther CW, 2005

USA

To determine the effects of a 1-yr intervention of dairy calcium on changes in body weight and fat mass in healthy women, aged 18–30 yrs.

Ages: 18-30 yrs (mean 20 yrs)

Total n completed = 41 in control, 44 in medium, 48 in high dairy

Randomized controlled trial for 1 year.

1) Control: Continue established dietary intake.

2) Medium dairy: Substitute dairy products to achieve calcium intake of approximately 1000-1100 mg/d and maintain isocaloric intake.

3) High dairy: Substitute dairy products to achieve calcium intake of 1300-1400 mg/d and maintain isocaloric intake.

Groups 2) and 3) instructed to increase intake of daily calcium by substituting dairy products rich in calcium, with an emphasis on non-fat and low-fat milk.

3 d food records to assess calcium intake

No significant change in 1 y body weight between groups (control: 0.8 ± 2.8 kg, medium-dairy group: 0.7 ± 3.0 kg, high-dairy group: 1.5 ± 4.1 kg).

Golley RK, 2012

Australia

To undertake a secondary analysis to evaluate the impact of changing children’s dairy food choices, in terms of fat type, on children’s total food intake and examine the contribution of dairy foods to energy and fat intake relative to other food groups

Ages: Families comprised one parent and their healthy children aged 4-13 yrs

Total n completed = 137 children

Cluster randomized controlled trial (secondary analysis) for 24 weeks.

1) Parents asked to change dairy foods they purchased for the family and offered to their children (i.e., replacing regular- with reduced- or low-fat varieties).

2) Individualized advice: Encouraged to replace screen-based activities with other sedentary activities, to try to avoid an increase in physical activity.

24 h recall

1) Week 12: Children in the intervention group consumed 1.0 (0.6, 1.3) servings per day more reduced-fat dairy vs. control group (P < 0.0001)

2) Week 24: Reduced fat dairy intake was higher in the intervention vs. control group by 0.8 (0.5, 1.1) servings per day, P < 0.0001.

3) Week 24: Contribution of total dairy to total saturated fat intake was significantly lower in the intervention group vs. the comparison group: 10 ± 11 % vs. 20 ± 14 %, P < 0.01.

Ebbeling C, 2006

USA

To test the hypothesis that a simple environmental intervention will significantly decrease SSB consumption and BMI among adolescents.

Ages: 13-18 yrs

Total n completed = 103

Randomized, controlled pilot study for 25 weeks.

1) Received weekly home deliveries of noncaloric beverages for 25 weeks (4 × 360 ml or 12 fl oz per referent serving). The target number of delivered servings was ~5 units/week.

2) Control: Continue usual beverage consumption habits.

1) 2x 24 h dietary recalls

2) Physical activity recall

1) NS in mean ± SEM BMI between intervention and control (0.07 ± 0.14 kg/m² vs. 0.21 ± 0.15 kg/m²(Δ -0.14 ± 0.21 kg/m², P > 0.05).

2) Mean change in energy intake was lower in the intervention vs. control group (-1201 ± 836 kJ vs. -185 ± 94 kJ, P < 0.001).

3) Intervention group increased non-caloric beverage intake vs. control (396 ± 493 ml/d vs. 78 ± 523 ml/d, P = 0.002).

Raben A, 2002

Denmark

To investigate the effect of long-term supplementation with drinks and foods containing either sucrose or artificial sweeteners on ad-libitum food intake and body weight in overweight subjects.

Ages: 20-50 yrs (mean 33 yrs in sucrose vs. 37 yrs in sweetener group)

Total n completed = 41

Parallel design with 2 intervention groups for 10 weeks in overweight adults.

1) Received supplemental drinks and foods containing sucrose (~70 % of the sucrose came from drinks and ~30 % came from solid foods to reach a sucrose intake of ~2 g/kg body weight; foods/drinks included soft drinks, fruit juices, yoghurt, ice-cream).

2) Received similar drinks and foods containing artificial sweeteners (in similar amounts to sucrose group).

1) 7 d dietary records for energy and nutrient intakes

2) 7 d diaries for monitoring hunger, fullness, palatability of the food, and wellbeing)

1) Energy intake from the sucrose supplements was ~3 times higher than that from the sweetener supplements (3349 ± 66 kJ vs. 963 ± 44 kJ, diet effect P < 0.0001).

2) Higher amounts of total carbohydrate (%E) consumed from the sucrose vs. sweetener supplements (89 ± 0 % vs. 52 ± 2 %, P < 0.05).

3) Total daily energy intake higher in the sucrose vs. sweetener group (11452 ± 551 kJ vs. 8656 ± 416 kJ, P = 0.03 diet × time interaction).

4) Total daily fat intake (% E) was lower in the sucrose vs. sweetener group (29 ± 1 % vs. 33 ± 1 %, P = 0.005 diet × time interaction).

5) Body weight increased in the sucrose group and decreased in the sweetener group (+1.6 kg vs. -1.0 kg, P < 0.0001).

Wilson J, 2000

USA

1) To examine the eating behavior of a large number of preschool children offered chocolate-flavored or plain milk at lunch.

2) To examine whether aspartame-sweetened (sugar-free) chocolate milk also induced an increase in energy intake during the meal

Ages: 1.5–5.5 yrs

Total n completed = 135

Randomized controlled trial

Four different menus served six times during a 12-week period, each menu being presented twice with each of three test beverages:

1) Plain milk (18.1 kcal/oz).

2) Sucrose-sweetened chocolate milk (29.4 kcal/oz).

3) Aspartame-sweetened chocolate milk (18.6 kcal/oz).

Weighed portions

1) The type of milk beverage served had no significant effect on the consumption of other food items offered at that meal.

2) Children consumed more energy (134-155 kcal vs. 48-66 kcal, P < 0.05) during meals in which sucrose-sweetened chocolate milk was served.

Harris J, 2011

USA

To test (1) whether children will consume low-sugar RTEC and (2) the effects of serving high- versus low-sugar cereals on the consumption of cereal, refined sugar, fresh fruit, and milk.

Ages: 5-12 yrs (mean 8.4 yrs)

Total n completed = 91

Randomized trial.

1) High-sugar RTEC (3 cereals offered, 11-12 g of sugar per serving, 28-33 g)

2) Low-sugar RTEC (3 cereals offered, 1-4 g of sugar per serving, 28-33 g)

Children poured their own cereal. Each place-setting contained an 8-oz carton of 1 % low-fat milk (245 g), a small container of orange juice (182–197 g), and bowls of precut strawberries (140 g) and bananas (111 g). A bowl of sugar packets and additional orange juice and milk cartons were placed in the middle of each table.

1) Sugar and calorie content obtained from nutrition facts panels on the cereals

2) US Department of Agriculture National Nutrient Database for Standard References for other breakfast items.

Children in the high sugar condition:

1) Consumed more RTEC vs. children in low sugar condition (mean (SD): 61.3 (39.1) vs. 34.6 (24.3), P < 0.001).

2) Consumed more refined sugar from RTEC vs. low sugar RTEC (22.9 (14.4) vs. 2.9 (2.6), P < 0.001).

3) Consumed more refined sugar overall (from RTEC and added sugar: 24.4 (15.1) vs. 12.5 (11.7), P < 0.001).

Children in the low sugar condition:

1) Added more sugar to their RTEC vs. children in the high sugar condition (9.6 (10.7) vs. 1.4 (2.8), P < 0.001)

2) NS between groups in other foods consumed (e.g. milk, fruit, orange juice).

Vitaglione P, 2010

Italy

To investigate new type of biscuit containing 5.2 % barley beta-glucan and its effect on appetite moods and food intake.

Ages: mean 18 yrs

Total n completed = 20

Five sessions in which subjects participated in a randomized order and with a week frequency.

Midmorning snack:

1) 628 kJ preload of barley beta-glucan-enriched biscuit.

2) 1884 kJ preload of barley beta-glucan-enriched biscuit (g/100 g: Energy: 1653 kJ; Protein: 6.1 g; Fat: 13.9 g; Carbohydrate: 61.4 g; Total dietary fibre: 12.6 g; soluble fibre: 8.3 g; beta-glucan: 5.2 g; insoluble fibre: 4.3 g).

3) Control biscuit (g/100 g: Energy: 1716 kJ; Protein: 8.6 g; Fat: 13.6 g; Carbohydrate: 63.2 g; Total dietary fibre: 2.5 g; soluble fibre: 1.2 g; beta-glucan: 0 g; insoluble fibre: 1.3 g).

Not reported

No effect of food intake between any of the snack groups.

Johnstone A, 2000

UK

To examine the effects of 1) ingesting mandatory snacks vs. no snacks; 2) the composition of isoenergetically-dense snacks high in protein, fat or carbohydrate, on food intake and energy intake in eight men with ad-libitum access to a diet of fixed composition.

Ages: mean age 27 yrs

Total n completed = 8 men

Subjects were required to consume three mandatory isoenergetically dense snacks of the same energy content at three fixed-time points; served as a salad, pate and a yoghurt-style drink.

1) High protein (total 1.88 MJ protein from snacks).

2) High carbohydrate (total 1.93 MJ carbohydrate from snacks).

3) High fat (total 1.92 MJ fat from snacks).

4) No snacks.

Not reported

1) Total daily energy intake (inclusive of snacks) was not significantly different across treatments (F(3,21) 0.55; P  = 0.654).

2) NS in mean ± SE weight change between groups (high protein: Δ +0.48 ± 0.06 kg; high carbohydrate: Δ +0.33 ± 0.05 kg; no snacks: Δ -0.16 ± 0.06 kg; high fat: Δ -0.03 ± 0.04 kg, P > 0.05).

Ortinau LC, 2013

USA

To evaluate the impact of a higher-protein afternoon snack on appetite control, delays in eating initiation, and subsequent energy intake compared to an isocaloric normal protein snack in healthy women.

Ages: mean 27 yrs

Total n completed = 32

Randomized crossover-design.

Afternoon yogurt snacks containing:

1) Normal protein yoghurt (5 g protein/170 g serve).

2) Higher-protein Greek yoghurt (14 g protein/170 g serve).

Visual analogue scales

1) NS ad-libitum dinner intake between the normal protein and high protein snacks (686 ± 33 kcal vs. 709 ± 34 kcal, P = 0.324).

Leahy KE, 2008

USA

To investigate the effects of reducing the energy density of a popular and familiar entrée—macaroni and cheese—on children’s energy intake at lunch.

Ages: 2-5 yrs (mean 3.9 yrs) in a university day-care facility

Total n completed = 77

Within-subjects crossover design:

All children received a standard breakfast and then a manipulated (energy density) entrée (macaroni and cheese, 300 g) 1 day per week for 7 weeks. Included in the meal was broccoli, applesauce, and milk.

1) Higher-energy-density entrée had 2.0 kcal/g.

2) Lower-energy-density entrée had 1.4 kcal/g.

Weighed food before and after eating

1) Decreasing the energy density of the macaroni and cheese by 30 % resulted in a 25 % (72.3 ± 8.3 kcal) decrease in energy consumed from the macaroni and cheese (P < 0.05) and total lunch intake by 18 % (P < 0.0001).

2) Compared with the higher-energy-density macaroni and cheese, children consumed an additional 10.1 ± 4.2 g of the lower-energy-density macaroni and cheese (P < 0.05).

Osterholt KM, 2007

USA

To test how short-term ad libitum intake is affected by variations in the air content of a snack food

Ages: 19-45 yrs (mean 27 yrs)

Total n completed = 28

Cross-over design with repeated measures within subjects.

Subjects consumed a snack on 4 separate afternoons at least 3 days apart (differing in amount of incorporated air).

Both snacks had an energy density of 5.7 kcal/g and contained 56 % of energy as fat.

Snacks differed slightly in sodium content (less-aerated: 1.0 % of weight; more-aerated: 1.3 % of weight). Subjects were served the same volume of each snack (approximately 1250 ml), but received 55 % less weight and energy when served the more-aerated snack rather than the less-aerated snack.

Weighed food before and after eating

1) Subjects consumed a mean of 70 ± 17 fewer kcal of the more-aerated snack than the less-aerated snack, equivalent to a 21 % decrease in energy intake (P = 0.0003).

2) By volume, consumption of the more-aerated snack was 239 ± 24 ml greater, equivalent to a 73 % increase in the volume consumed (P < 0.0001).

3) NS in subsequent snack intake (data not reported in paper).