To investigate the effects of a sugar-sweetened beverage (SSB) tax and a nutrient profiling tax on consumer food purchases in a virtual supermarket.

A randomised controlled trial was conducted with a control condition with regular food prices (n 152), an SSB tax condition (n 130) and a nutrient profiling tax condition based on Nutri-Score (n 112). Participants completed a weekly grocery shop for their household. Primary outcome measures were SSB purchases (ordinal variable) and the overall healthiness of the total shopping basket (proportion of total unit food items classified as healthy). The secondary outcome measure was the energy (kcal) content of the total shopping basket. Data were analysed using regression analyses.

Three-dimensional virtual supermarket.

Dutch adults aged ≥18 years are being responsible for grocery shopping in their household (n 394).

The SSB tax (OR = 1·62, (95 % CI 1·03, 2·54)) and the nutrient profiling tax (OR = 1·88, (95 %CI 1·17, 3·02)) increased the likelihood of being in a lower-level category of SSB purchases. The overall healthiness of the total shopping basket was higher (+2·7 percent point, (95 % CI 0·1, 5·3)), and the energy content was lower (−3301 kcal, (95 % CI −6425, −177)) for participants in the nutrient profiling tax condition than for those in the control condition. The SSB tax did not affect the overall healthiness and energy content of the total shopping basket (P > 0·05).

A nutrient profiling tax targeting a wide range of foods and beverages with a low nutritional quality seems to have larger beneficial effects on consumer food purchases than taxation of SSB alone.

To examine the availability of packaged food products in New Zealand supermarkets by level of industrial processing, nutrient profiling score (NPSC), price (energy, unit and serving costs) and brand variety.

Secondary analysis of cross-sectional survey data on packaged supermarket food and non-alcoholic beverages. Products were classified according to level of industrial processing (minimally, culinary and ultra-processed) and their NPSC.

Packaged foods available in four major supermarkets in Auckland, New Zealand.

Packaged supermarket food products for the years 2011 and 2013.

The majority (84 % in 2011 and 83 % in 2013) of packaged foods were classified as ultra-processed. A significant positive association was found between the level of industrial processing and NPSC, i.e. ultra-processed foods had a worse nutrient profile (NPSC=11·63) than culinary processed foods (NPSC=7·95), which in turn had a worse nutrient profile than minimally processed foods (NPSC=3·27), P<0·001. No clear associations were observed between the three price measures and level of processing. The study observed many variations of virtually the same product. The ten largest food manufacturers produced 35 % of all packaged foods available.

In New Zealand supermarkets, ultra-processed foods comprise the largest proportion of packaged foods and are less healthy than less processed foods. The lack of significant price difference between ultra- and less processed foods suggests ultra-processed foods might provide time-poor consumers with more value for money. These findings highlight the need to improve the supermarket food supply by reducing numbers of ultra-processed foods and by reformulating products to improve their nutritional profile.

To study differences in the role of price and value in food choice between low-income and higher-income consumers and to study the perception of consumers about pricing strategies that are of relevance during grocery shopping.

A cross-sectional study was conducted using structured, written questionnaires. Food choice motives as well as price perceptions and opinion on pricing strategies were measured.

The study was carried out in point-of-purchase settings, i.e. supermarkets, fast-food restaurants and sports canteens.

Adults (n 159) visiting a point-of-purchase setting were included.

Price is an important factor in food choice, especially for low-income consumers. Low-income consumers were significantly more conscious of value and price than higher-income consumers. The most attractive strategies, according to the consumers, were discounting healthy food more often and applying a lower VAT (Value Added Tax) rate on healthy food. Low-income consumers differ in their preferences for pricing strategies.

Since price is more important for low-income consumers we recommend mainly focusing on their preferences and needs.

To examine the association between energy density and energy costs in single food items and composed diets, and to explore differences in energy density and energy cost between income levels.

A cross-sectional study using data from two Dutch cohort studies and recent national food prices. Food prices were retrieved from two market leader supermarkets. Data on dietary intake were measured using a computerized face-to-face interview (cohort 1) and 24 h recalls (cohort 2).

The Netherlands.

A sample of 373 young adults from the Amsterdam Growth and Health Longitudinal Study (AGHLS, measured in 2000) and a sample of 200 community-dwelling elderly from the Longitudinal Ageing Study Amsterdam (LASA, measured in 2007).

We found significant inverse associations between energy density and energy costs in single food items (r = −0·436, P < 0·01) and composed diets (AGHLS men r = −0·505, women r = −0·413, P < 0·001; LASA men r = −0·559, women r = −0·562, P < 0·001). Furthermore, we found that people stratified into higher energy density quartiles consumed significantly more energy per day, less fruits and vegetables, and had significantly lower diet costs. Explorative analyses on income did not reveal significant differences regarding energy density, costs, or fruit and vegetable intake.

In the Netherlands also, energy density was inversely related with energy costs, implying that healthier diets cost more. However, we could not find differences in energy density or costs between income levels. Future research, using precise food expenditures, is of main importance in studying the economics of obesity and in the aim of making the healthier choice easier.