Consumer giants, which are facing increased competition from upstart brands, are buying growth where they cannot create it. The result: a new report found deal activity in the sector reached a 15-year high last year.

Deals in the consumer goods industry rose 45 percent over the year prior, according to a survey from OC&C Strategy Consultants released Monday. The value deals of jumped 190 percent.

While the companies are all seeking growth, the deals reflect an array of strategies. Some are investing in digital companies to help more rapidly adjust to changing consumers. Others are buying companies in faster-growing regions, like the emerging markets, or within on-trend categories, like organic food.

"The balance of power has shifted as some of the traditional scale advantages that the major brand owners enjoyed (like having scale manufacturing, big salesforces, ability to advertise on TV, attract good people to work for them) have been eroded by digital technologies, which have enabled smaller businesses to grow more successfully than in the past," said Will Hayllar, co-leader of the global consumer goods team at OC&C, in an email.

Nestle invested in three meal subscription services: Sun Basket, Freshly and Gousto. Campbell Soup shelled out $700 million for organic soup company Pacific Foods. Japan Tobacco acquired a 31 percent stake in Ethiopia's National Tobacco Enterprise.

“While the underlying challenges ... to restore organic growth and satisfy activist investors seeking margin improvement have not gone away ... [companies] are actively addressing those challenges and using M&A as a key tool to do so," Hayllar said in a press release.

The OC&C survey, now in its 16th year, analyzed the top 50 international consumer goods companies based on their 2017 sales. Last year, 10 of the 23 food and drinks companies surveyed by OC&C had declining revenue. The beer and spirits category fared better, with all seven companies surveyed by OC&C increasing revenue in 2017.

All told, consumer companies reported sales growth of only 2.6 percent last year, while volume, which strips out the impact of currency and price, inched up 0.6 percent. Including the boost from dealmaking, though, the companies grew sales 5.7 percent, the highest level since 2011.

Anheuser-Busch InBev, which in 2016 closed its more than $100 billion acquisition of rival SAB Miller, was one of those beneficiaries. The beer giant reported a 24 percent growth rate last year, but OC&C estimates that only 5.1 percent of that growth was due to organic sales.

Acquisitions in the beer and spirits and tobacco sectors helped drive industry sales up 21.8 percent.

Consumer companies sold as well as acquired, in hopes of honing their focus. The food and drinks sector was responsible for 17 out of 24 total divestitures from the companies analyzed.

"Partly because of these pressures many of the big players that do have presence across categories have been selling elements of their food businesses and investing to acquire in other categories where they see more growth and margin potential," Hayllar said in his email.

Unilever, for example, sold its spreads and dressings business to private equity group KKR for more than $8 billion. Also in 2017, it bought several other companies, including Tazo Tea, a specialty tea company, for $384 million and Sir Kensington's, a condiment maker, for $140 million.

The study noted companies' growing focus on sustainability. In the U.K. the trend is in part driven by a BBC documentary series "Blue Planet II," which looked at the ecological effects of plastic pollution. However, millennial consumers in the U.S., who tend to be in their early 20s to late 30s, also tend to be more focused on environmental issues than prior generations.

One example cited by the study was an alliance Nestle formed last year with fellow water bottler Danone and start-up Origin Materials to create a PET plastic bottle that hopes to be entirely bio-based after 2022.